Table of Contents
+ ++ The Internet Domain Name System (DNS) + consists of the syntax + to specify the names of entities in the Internet in a hierarchical + manner, the rules used for delegating authority over names, and the + system implementation that actually maps names to Internet + addresses. DNS data is maintained in a + group of distributed + hierarchical databases. +
+ ++ The Berkeley Internet Name Domain + (BIND) implements a + domain name server for a number of operating systems. This + document provides basic information about the installation and + care of the Internet Systems Consortium (ISC) + BIND version 9 software package for + system administrators. +
+This version of the manual corresponds to BIND version 9.11.
++ In this document, Chapter 1 introduces + the basic DNS and BIND concepts. Chapter 2 + describes resource requirements for running BIND in various + environments. Information in Chapter 3 is + task-oriented in its presentation and is + organized functionally, to aid in the process of installing the + BIND 9 software. The task-oriented + section is followed by + Chapter 4, which contains more advanced + concepts that the system administrator may need for implementing + certain options. Chapter 5 + describes the BIND 9 lightweight + resolver. The contents of Chapter 6 are + organized as in a reference manual to aid in the ongoing + maintenance of the software. Chapter 7 addresses + security considerations, and + Chapter 8 contains troubleshooting help. The + main body of the document is followed by several + appendices which contain useful reference + information, such as a bibliography and + historic information related to BIND + and the Domain Name + System. +
++ In this document, we use the following general typographic + conventions: +
+ +|
+ + To describe: + + |
+
+ + We use the style: + + |
+
|
+ + a pathname, filename, URL, hostname, + mailing list name, or new term or concept + + |
+
+
+ |
+
|
+ + literal user + input + + |
+
+
+ |
+
|
+ + program output + + |
+
+
+ |
+
+ The following conventions are used in descriptions of the + BIND configuration file:
+|
+ + To describe: + + |
+
+ + We use the style: + + |
+
|
+ + keywords + + |
+
+
+ |
+
|
+ + variables + + |
+
+
+ |
+
|
+ + Optional input + + |
+
+ + [Text is enclosed in square brackets] + + |
+
+
++ The purpose of this document is to explain the installation + and upkeep of the BIND (Berkeley Internet + Name Domain) software package, and we + begin by reviewing the fundamentals of the Domain Name System + (DNS) as they relate to BIND. +
+ ++ The Domain Name System (DNS) is a hierarchical, distributed + database. It stores information for mapping Internet host names to + IP + addresses and vice versa, mail routing information, and other data + used by Internet applications. +
+ ++ Clients look up information in the DNS by calling a + resolver library, which sends queries to one or + more name servers and interprets the responses. + The BIND 9 software distribution + contains a name server, named, and a set + of associated tools. +
+ ++ The data stored in the DNS is identified by domain names that are organized as a tree according to + organizational or administrative boundaries. Each node of the tree, + called a domain, is given a label. The domain + name of the + node is the concatenation of all the labels on the path from the + node to the root node. This is represented + in written form as a string of labels listed from right to left and + separated by dots. A label need only be unique within its parent + domain. +
+ +
+ For example, a domain name for a host at the
+ company Example, Inc. could be
+ ourhost.example.com,
+ where com is the
+ top level domain to which
+ ourhost.example.com belongs,
+ example is
+ a subdomain of com, and
+ ourhost is the
+ name of the host.
+
+ For administrative purposes, the name space is partitioned into + areas called zones, each starting at a node and + extending down to the leaf nodes or to nodes where other zones + start. + The data for each zone is stored in a name server, which answers queries about the zone using the + DNS protocol. +
+ ++ The data associated with each domain name is stored in the + form of resource records (RRs). + Some of the supported resource record types are described in + the section called “Types of Resource Records and When to Use Them”. +
+ ++ For more detailed information about the design of the DNS and + the DNS protocol, please refer to the standards documents listed in + the section called “Request for Comments (RFCs)”. +
++ To properly operate a name server, it is important to understand + the difference between a zone + and a domain. +
+ ++ As stated previously, a zone is a point of delegation in + the DNS tree. A zone consists of + those contiguous parts of the domain + tree for which a name server has complete information and over which + it has authority. It contains all domain names from a certain point + downward in the domain tree except those which are delegated to + other zones. A delegation point is marked by one or more + NS records in the + parent zone, which should be matched by equivalent NS records at + the root of the delegated zone. +
+ +
+ For instance, consider the example.com
+ domain which includes names
+ such as host.aaa.example.com and
+ host.bbb.example.com even though
+ the example.com zone includes
+ only delegations for the aaa.example.com and
+ bbb.example.com zones. A zone can
+ map
+ exactly to a single domain, but could also include only part of a
+ domain, the rest of which could be delegated to other
+ name servers. Every name in the DNS
+ tree is a
+ domain, even if it is
+ terminal, that is, has no
+ subdomains. Every subdomain is a domain and
+ every domain except the root is also a subdomain. The terminology is
+ not intuitive and we suggest that you read RFCs 1033, 1034 and 1035
+ to
+ gain a complete understanding of this difficult and subtle
+ topic.
+
+ Though BIND is called a "domain name
+ server",
+ it deals primarily in terms of zones. The master and slave
+ declarations in the named.conf file
+ specify
+ zones, not domains. When you ask some other site if it is willing to
+ be a slave server for your domain, you are
+ actually asking for slave service for some collection of zones.
+
+ Each zone is served by at least + one authoritative name server, + which contains the complete data for the zone. + To make the DNS tolerant of server and network failures, + most zones have two or more authoritative servers, on + different networks. +
+ ++ Responses from authoritative servers have the "authoritative + answer" (AA) bit set in the response packets. This makes them + easy to identify when debugging DNS configurations using tools like + dig (the section called “Diagnostic Tools”). +
+ ++ The authoritative server where the master copy of the zone + data is maintained is called the + primary master server, or simply the + primary. Typically it loads the zone + contents from some local file edited by humans or perhaps + generated mechanically from some other local file which is + edited by humans. This file is called the + zone file or + master file. +
+ ++ In some cases, however, the master file may not be edited + by humans at all, but may instead be the result of + dynamic update operations. +
++ The other authoritative servers, the slave + servers (also known as secondary servers) + load + the zone contents from another server using a replication process + known as a zone transfer. Typically the data + are + transferred directly from the primary master, but it is also + possible + to transfer it from another slave. In other words, a slave server + may itself act as a master to a subordinate slave server. +
++ Usually all of the zone's authoritative servers are listed in + NS records in the parent zone. These NS records constitute + a delegation of the zone from the parent. + The authoritative servers are also listed in the zone file itself, + at the top level or apex + of the zone. You can list servers in the zone's top-level NS + records that are not in the parent's NS delegation, but you cannot + list servers in the parent's delegation that are not present at + the zone's top level. +
+ ++ A stealth server is a server that is + authoritative for a zone but is not listed in that zone's NS + records. Stealth servers can be used for keeping a local copy of + a + zone to speed up access to the zone's records or to make sure that + the + zone is available even if all the "official" servers for the zone + are + inaccessible. +
+ ++ A configuration where the primary master server itself is a + stealth server is often referred to as a "hidden primary" + configuration. One use for this configuration is when the primary + master + is behind a firewall and therefore unable to communicate directly + with the outside world. +
+ ++ The resolver libraries provided by most operating systems are + stub resolvers, meaning that they are not + capable of + performing the full DNS resolution process by themselves by talking + directly to the authoritative servers. Instead, they rely on a + local + name server to perform the resolution on their behalf. Such a + server + is called a recursive name server; it performs + recursive lookups for local clients. +
+ ++ To improve performance, recursive servers cache the results of + the lookups they perform. Since the processes of recursion and + caching are intimately connected, the terms + recursive server and + caching server are often used synonymously. +
+ ++ The length of time for which a record may be retained in + the cache of a caching name server is controlled by the + Time To Live (TTL) field associated with each resource record. +
+ ++ Even a caching name server does not necessarily perform + the complete recursive lookup itself. Instead, it can + forward some or all of the queries + that it cannot satisfy from its cache to another caching name + server, + commonly referred to as a forwarder. +
+ ++ There may be one or more forwarders, + and they are queried in turn until the list is exhausted or an + answer + is found. Forwarders are typically used when you do not + wish all the servers at a given site to interact directly with the + rest of + the Internet servers. A typical scenario would involve a number + of internal DNS servers and an + Internet firewall. Servers unable + to pass packets through the firewall would forward to the server + that can do it, and that server would query the Internet DNS servers + on the internal server's behalf. +
++ The BIND name server can + simultaneously act as + a master for some zones, a slave for other zones, and as a caching + (recursive) server for a set of local clients. +
+ ++ However, since the functions of authoritative name service + and caching/recursive name service are logically separate, it is + often advantageous to run them on separate server machines. + + A server that only provides authoritative name service + (an authoritative-only server) can run with + recursion disabled, improving reliability and security. + + A server that is not authoritative for any zones and only provides + recursive service to local + clients (a caching-only server) + does not need to be reachable from the Internet at large and can + be placed inside a firewall. +
+ +BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch02.html b/doc/arm/Bv9ARM.ch02.html new file mode 100644 index 0000000000000000000000000000000000000000..c9a5a9e4b2a77ccc13990e3c0b39b568d5210bc5 --- /dev/null +++ b/doc/arm/Bv9ARM.ch02.html @@ -0,0 +1,151 @@ + + + + + +Table of Contents
+ ++ DNS hardware requirements have + traditionally been quite modest. + For many installations, servers that have been pensioned off from + active duty have performed admirably as DNS servers. +
++ The DNSSEC features of BIND 9 + may prove to be quite + CPU intensive however, so organizations that make heavy use of these + features may wish to consider larger systems for these applications. + BIND 9 is fully multithreaded, allowing + full utilization of + multiprocessor systems for installations that need it. +
++ CPU requirements for BIND 9 range from + i486-class machines + for serving of static zones without caching, to enterprise-class + machines if you intend to process many dynamic updates and DNSSEC + signed zones, serving many thousands of queries per second. +
++ The memory of the server has to be large enough to fit the + cache and zones loaded off disk. The max-cache-size + option can be used to limit the amount of memory used by the cache, + at the expense of reducing cache hit rates and causing more DNS + traffic. + It is still good practice to have enough memory to load + all zone and cache data into memory — unfortunately, the best + way + to determine this for a given installation is to watch the name server + in operation. After a few weeks the server process should reach + a relatively stable size where entries are expiring from the cache as + fast as they are being inserted. +
+ ++ For name server intensive environments, there are two alternative + configurations that may be used. The first is where clients and + any second-level internal name servers query a main name server, which + has enough memory to build a large cache. This approach minimizes + the bandwidth used by external name lookups. The second alternative + is to set up second-level internal name servers to make queries + independently. + In this configuration, none of the individual machines needs to + have as much memory or CPU power as in the first alternative, but + this has the disadvantage of making many more external queries, + as none of the name servers share their cached data. +
++ ISC BIND 9 compiles and runs on a large + number + of Unix-like operating systems and on + Microsoft Windows Server 2003 and 2008, and Windows XP and Vista. + For an up-to-date + list of supported systems, see the README file in the top level + directory + of the BIND 9 source distribution. +
+BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch03.html b/doc/arm/Bv9ARM.ch03.html new file mode 100644 index 0000000000000000000000000000000000000000..e4ef58d274a90e76371d76dc9fedd3b3baa7ee30 --- /dev/null +++ b/doc/arm/Bv9ARM.ch03.html @@ -0,0 +1,764 @@ + + + + + +Table of Contents
+ ++ In this chapter we provide some suggested configurations along + with guidelines for their use. We suggest reasonable values for + certain option settings. +
+ ++ The following sample configuration is appropriate for a caching-only + name server for use by clients internal to a corporation. All + queries + from outside clients are refused using the allow-query + option. Alternatively, the same effect could be achieved using + suitable + firewall rules. +
+ +
+// Two corporate subnets we wish to allow queries from.
+acl corpnets { 192.168.4.0/24; 192.168.7.0/24; };
+options {
+ // Working directory
+ directory "/etc/namedb";
+
+ allow-query { corpnets; };
+};
+// Provide a reverse mapping for the loopback
+// address 127.0.0.1
+zone "0.0.127.in-addr.arpa" {
+ type master;
+ file "localhost.rev";
+ notify no;
+};
+
+
+
+ This sample configuration is for an authoritative-only server
+ that is the master server for "example.com"
+ and a slave for the subdomain "eng.example.com".
+
+options {
+ // Working directory
+ directory "/etc/namedb";
+ // Do not allow access to cache
+ allow-query-cache { none; };
+ // This is the default
+ allow-query { any; };
+ // Do not provide recursive service
+ recursion no;
+};
+
+// Provide a reverse mapping for the loopback
+// address 127.0.0.1
+zone "0.0.127.in-addr.arpa" {
+ type master;
+ file "localhost.rev";
+ notify no;
+};
+// We are the master server for example.com
+zone "example.com" {
+ type master;
+ file "example.com.db";
+ // IP addresses of slave servers allowed to
+ // transfer example.com
+ allow-transfer {
+ 192.168.4.14;
+ 192.168.5.53;
+ };
+};
+// We are a slave server for eng.example.com
+zone "eng.example.com" {
+ type slave;
+ file "eng.example.com.bk";
+ // IP address of eng.example.com master server
+ masters { 192.168.4.12; };
+};
+
+
+ + A primitive form of load balancing can be achieved in + the DNS by using multiple records + (such as multiple A records) for one name. +
+ ++ For example, if you have three WWW servers with network addresses + of 10.0.0.1, 10.0.0.2 and 10.0.0.3, a set of records such as the + following means that clients will connect to each machine one third + of the time: +
+ +|
+ + Name + + |
+
+ + TTL + + |
+
+ + CLASS + + |
+
+ + TYPE + + |
+
+ + Resource Record (RR) Data + + |
+
|
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
+ When a resolver queries for these records, BIND will rotate + them and respond to the query with the records in a different + order. In the example above, clients will randomly receive + records in the order 1, 2, 3; 2, 3, 1; and 3, 1, 2. Most clients + will use the first record returned and discard the rest. +
++ For more detail on ordering responses, check the + rrset-order sub-statement in the + options statement, see + RRset Ordering. +
+ ++ This section describes several indispensable diagnostic, + administrative and monitoring tools available to the system + administrator for controlling and debugging the name server + daemon. +
++ The dig, host, and + nslookup programs are all command + line tools + for manually querying name servers. They differ in style and + output format. +
+ ++ dig + is the most versatile and complete of these lookup tools. + It has two modes: simple interactive + mode for a single query, and batch mode which executes a + query for + each in a list of several query lines. All query options are + accessible + from the command line. +
+
+ dig
+ [@server]
+ domain
+ [query-type]
+ [query-class]
+ [+query-option]
+ [-dig-option]
+ [%comment]
+
+ The usual simple use of dig will take the form +
++ dig @server domain query-type query-class +
++ For more information and a list of available commands and + options, see the dig man + page. +
++ The host utility emphasizes + simplicity + and ease of use. By default, it converts + between host names and Internet addresses, but its + functionality + can be extended with the use of options. +
+
+ host
+ [-aCdlnrsTwv]
+ [-c class]
+ [-N ndots]
+ [-t type]
+ [-W timeout]
+ [-R retries]
+ [-m flag]
+ [-4]
+ [-6]
+ hostname
+ [server]
+
+ For more information and a list of available commands and + options, see the host man + page. +
+nslookup + has two modes: interactive and + non-interactive. Interactive mode allows the user to + query name servers for information about various + hosts and domains or to print a list of hosts in a + domain. Non-interactive mode is used to print just + the name and requested information for a host or + domain. +
+
+ nslookup
+ [-option...]
+ [
+ [host-to-find]
+ | [- [server]]
+ ]
+
+ Interactive mode is entered when no arguments are given (the + default name server will be used) or when the first argument + is a + hyphen (`-') and the second argument is the host name or + Internet address + of a name server. +
++ Non-interactive mode is used when the name or Internet + address + of the host to be looked up is given as the first argument. + The + optional second argument specifies the host name or address + of a name server. +
++ Due to its arcane user interface and frequently inconsistent + behavior, we do not recommend the use of nslookup. + Use dig instead. +
++ Administrative tools play an integral part in the management + of a server. +
+
+ The named-checkconf program
+ checks the syntax of a named.conf file.
+
+ named-checkconf
+ [-jvz]
+ [-t directory]
+ [filename]
+
+ The named-checkzone program + checks a master file for + syntax and consistency. +
+
+ named-checkzone
+ [-djqvD]
+ [-c class]
+ [-o output]
+ [-t directory]
+ [-w directory]
+ [-k (ignore|warn|fail)]
+ [-n (ignore|warn|fail)]
+ [-W (ignore|warn)]
+ zone
+ [filename]
+
+ Similar to named-checkzone, but + it always dumps the zone content to a specified file + (typically in a different format). +
++ The remote name daemon control + (rndc) program allows the + system + administrator to control the operation of a name server. + Since BIND 9.2, rndc + supports all the commands of the BIND 8 ndc + utility except ndc start and + ndc restart, which were also + not supported in ndc's + channel mode. + If you run rndc without any + options + it will display a usage message as follows: +
+
+ rndc
+ [-c config]
+ [-s server]
+ [-p port]
+ [-y key]
+ command
+ [command...]
+
See rndc(8) for details of + the available rndc commands. +
+ +
+ rndc requires a configuration file,
+ since all
+ communication with the server is authenticated with
+ digital signatures that rely on a shared secret, and
+ there is no way to provide that secret other than with a
+ configuration file. The default location for the
+ rndc configuration file is
+ /etc/rndc.conf, but an
+ alternate
+ location can be specified with the -c
+ option. If the configuration file is not found,
+ rndc will also look in
+ /etc/rndc.key (or whatever
+ sysconfdir was defined when
+ the BIND build was
+ configured).
+ The rndc.key file is
+ generated by
+ running rndc-confgen -a as
+ described in
+ the section called “controls Statement Definition and
+ Usage”.
+
+ The format of the configuration file is similar to
+ that of named.conf, but
+ limited to
+ only four statements, the options,
+ key, server and
+ include
+ statements. These statements are what associate the
+ secret keys to the servers with which they are meant to
+ be shared. The order of statements is not
+ significant.
+
+ The options statement has
+ three clauses:
+ default-server, default-key,
+ and default-port.
+ default-server takes a
+ host name or address argument and represents the server
+ that will
+ be contacted if no -s
+ option is provided on the command line.
+ default-key takes
+ the name of a key as its argument, as defined by a key statement.
+ default-port specifies the
+ port to which
+ rndc should connect if no
+ port is given on the command line or in a
+ server statement.
+
+ The key statement defines a
+ key to be used
+ by rndc when authenticating
+ with
+ named. Its syntax is
+ identical to the
+ key statement in named.conf.
+ The keyword key is
+ followed by a key name, which must be a valid
+ domain name, though it need not actually be hierarchical;
+ thus,
+ a string like "rndc_key" is a valid
+ name.
+ The key statement has two
+ clauses:
+ algorithm and secret.
+ While the configuration parser will accept any string as the
+ argument
+ to algorithm, currently only the strings
+ "hmac-md5",
+ "hmac-sha1",
+ "hmac-sha224",
+ "hmac-sha256",
+ "hmac-sha384"
+ and "hmac-sha512"
+ have any meaning. The secret is a base-64 encoded string
+ as specified in RFC 3548.
+
+ The server statement
+ associates a key
+ defined using the key
+ statement with a server.
+ The keyword server is followed by a
+ host name or address. The server statement
+ has two clauses: key and port.
+ The key clause specifies the
+ name of the key
+ to be used when communicating with this server, and the
+ port clause can be used to
+ specify the port rndc should
+ connect
+ to on the server.
+
+ A sample minimal configuration file is as follows: +
+ +
+key rndc_key {
+ algorithm "hmac-sha256";
+ secret
+ "c3Ryb25nIGVub3VnaCBmb3IgYSBtYW4gYnV0IG1hZGUgZm9yIGEgd29tYW4K";
+};
+options {
+ default-server 127.0.0.1;
+ default-key rndc_key;
+};
+
+
+
+ This file, if installed as /etc/rndc.conf,
+ would allow the command:
+
+ $ rndc reload
+
+ to connect to 127.0.0.1 port 953 and cause the name server + to reload, if a name server on the local machine were + running with + following controls statements: +
+ +
+controls {
+ inet 127.0.0.1
+ allow { localhost; } keys { rndc_key; };
+};
+
+
+
+ and it had an identical key statement for
+ rndc_key.
+
+ Running the rndc-confgen
+ program will
+ conveniently create a rndc.conf
+ file for you, and also display the
+ corresponding controls
+ statement that you need to
+ add to named.conf.
+ Alternatively,
+ you can run rndc-confgen -a
+ to set up
+ a rndc.key file and not
+ modify
+ named.conf at all.
+
+ Certain UNIX signals cause the name server to take specific + actions, as described in the following table. These signals can + be sent using the kill command. +
+|
+ SIGHUP + |
+
+
+ Causes the server to read |
+
|
+ SIGTERM + |
+
+ + Causes the server to clean up and exit. + + |
+
|
+ SIGINT + |
+
+ + Causes the server to clean up and exit. + + |
+
BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch04.html b/doc/arm/Bv9ARM.ch04.html new file mode 100644 index 0000000000000000000000000000000000000000..b3eb8278c30c302da9d2df84d98233edba40dddf --- /dev/null +++ b/doc/arm/Bv9ARM.ch04.html @@ -0,0 +1,2875 @@ + + + + + +Table of Contents
++ DNS NOTIFY is a mechanism that allows master + servers to notify their slave servers of changes to a zone's data. In + response to a NOTIFY from a master server, the + slave will check to see that its version of the zone is the + current version and, if not, initiate a zone transfer. +
+ ++ For more information about DNS + NOTIFY, see the description of the + notify option in the section called “Boolean Options” and + the description of the zone option also-notify in + the section called “Zone Transfers”. The NOTIFY + protocol is specified in RFC 1996. +
+ ++ As a slave zone can also be a master to other slaves, named, + by default, sends NOTIFY messages for every zone + it loads. Specifying notify master-only; will + cause named to only send NOTIFY for master + zones that it loads. +
++ Dynamic Update is a method for adding, replacing or deleting + records in a master server by sending it a special form of DNS + messages. The format and meaning of these messages is specified + in RFC 2136. +
+ ++ Dynamic update is enabled by including an + allow-update or an update-policy + clause in the zone statement. +
+ +
+ If the zone's update-policy is set to
+ local, updates to the zone
+ will be permitted for the key local-ddns,
+ which will be generated by named at startup.
+ See the section called “Dynamic Update Policies” for more details.
+
+ Dynamic updates using Kerberos signed requests can be made + using the TKEY/GSS protocol by setting either the + tkey-gssapi-keytab option, or alternatively + by setting both the tkey-gssapi-credential + and tkey-domain options. Once enabled, + Kerberos signed requests will be matched against the update + policies for the zone, using the Kerberos principal as the + signer for the request. +
+ ++ Updating of secure zones (zones using DNSSEC) follows RFC + 3007: RRSIG, NSEC and NSEC3 records affected by updates are + automatically regenerated by the server using an online + zone key. Update authorization is based on transaction + signatures and an explicit server policy. +
+ +
+ All changes made to a zone using dynamic update are stored
+ in the zone's journal file. This file is automatically created
+ by the server when the first dynamic update takes place.
+ The name of the journal file is formed by appending the extension
+ .jnl to the name of the
+ corresponding zone
+ file unless specifically overridden. The journal file is in a
+ binary format and should not be edited manually.
+
+ The server will also occasionally write ("dump")
+ the complete contents of the updated zone to its zone file.
+ This is not done immediately after
+ each dynamic update, because that would be too slow when a large
+ zone is updated frequently. Instead, the dump is delayed by
+ up to 15 minutes, allowing additional updates to take place.
+ During the dump process, transient files will be created
+ with the extensions .jnw and
+ .jbk; under ordinary circumstances, these
+ will be removed when the dump is complete, and can be safely
+ ignored.
+
+ When a server is restarted after a shutdown or crash, it will replay + the journal file to incorporate into the zone any updates that + took + place after the last zone dump. +
+ ++ Changes that result from incoming incremental zone transfers are + also + journaled in a similar way. +
+ ++ The zone files of dynamic zones cannot normally be edited by + hand because they are not guaranteed to contain the most recent + dynamic changes — those are only in the journal file. + The only way to ensure that the zone file of a dynamic zone + is up to date is to run rndc stop. +
+ +
+ If you have to make changes to a dynamic zone
+ manually, the following procedure will work:
+ Disable dynamic updates to the zone using
+ rndc freeze zone.
+ This will update the zone's master file with the changes
+ stored in its .jnl file.
+ Edit the zone file. Run
+ rndc thaw zone
+ to reload the changed zone and re-enable dynamic updates.
+
+ rndc sync zone
+ will update the zone file with changes from the journal file
+ without stopping dynamic updates; this may be useful for viewing
+ the current zone state. To remove the .jnl
+ file after updating the zone file, use
+ rndc sync -clean.
+
+ The incremental zone transfer (IXFR) protocol is a way for + slave servers to transfer only changed data, instead of having to + transfer the entire zone. The IXFR protocol is specified in RFC + 1995. See Proposed Standards. +
+ +
+ When acting as a master, BIND 9
+ supports IXFR for those zones
+ where the necessary change history information is available. These
+ include master zones maintained by dynamic update and slave zones
+ whose data was obtained by IXFR. For manually maintained master
+ zones, and for slave zones obtained by performing a full zone
+ transfer (AXFR), IXFR is supported only if the option
+ ixfr-from-differences is set
+ to yes.
+
+ When acting as a slave, BIND 9 will + attempt to use IXFR unless + it is explicitly disabled. For more information about disabling + IXFR, see the description of the request-ixfr clause + of the server statement. +
++ Setting up different views, or visibility, of the DNS space to + internal and external resolvers is usually referred to as a + Split DNS setup. There are several + reasons an organization would want to set up its DNS this way. +
++ One common reason for setting up a DNS system this way is + to hide "internal" DNS information from "external" clients on the + Internet. There is some debate as to whether or not this is actually + useful. + Internal DNS information leaks out in many ways (via email headers, + for example) and most savvy "attackers" can find the information + they need using other means. + However, since listing addresses of internal servers that + external clients cannot possibly reach can result in + connection delays and other annoyances, an organization may + choose to use a Split DNS to present a consistent view of itself + to the outside world. +
++ Another common reason for setting up a Split DNS system is + to allow internal networks that are behind filters or in RFC 1918 + space (reserved IP space, as documented in RFC 1918) to resolve DNS + on the Internet. Split DNS can also be used to allow mail from outside + back in to the internal network. +
+
+ Let's say a company named Example, Inc.
+ (example.com)
+ has several corporate sites that have an internal network with
+ reserved
+ Internet Protocol (IP) space and an external demilitarized zone (DMZ),
+ or "outside" section of a network, that is available to the public.
+
+ Example, Inc. wants its internal clients + to be able to resolve external hostnames and to exchange mail with + people on the outside. The company also wants its internal resolvers + to have access to certain internal-only zones that are not available + at all outside of the internal network. +
++ In order to accomplish this, the company will set up two sets + of name servers. One set will be on the inside network (in the + reserved + IP space) and the other set will be on bastion hosts, which are + "proxy" + hosts that can talk to both sides of its network, in the DMZ. +
+
+ The internal servers will be configured to forward all queries,
+ except queries for site1.internal, site2.internal, site1.example.com,
+ and site2.example.com, to the servers
+ in the
+ DMZ. These internal servers will have complete sets of information
+ for site1.example.com, site2.example.com, site1.internal,
+ and site2.internal.
+
+ To protect the site1.internal and site2.internal domains,
+ the internal name servers must be configured to disallow all queries
+ to these domains from any external hosts, including the bastion
+ hosts.
+
+ The external servers, which are on the bastion hosts, will
+ be configured to serve the "public" version of the site1 and site2.example.com zones.
+ This could include things such as the host records for public servers
+ (www.example.com and ftp.example.com),
+ and mail exchange (MX) records (a.mx.example.com and b.mx.example.com).
+
+ In addition, the public site1 and site2.example.com zones
+ should have special MX records that contain wildcard (`*') records
+ pointing to the bastion hosts. This is needed because external mail
+ servers do not have any other way of looking up how to deliver mail
+ to those internal hosts. With the wildcard records, the mail will
+ be delivered to the bastion host, which can then forward it on to
+ internal hosts.
+
+ Here's an example of a wildcard MX record: +
+* IN MX 10 external1.example.com.+
+ Now that they accept mail on behalf of anything in the internal + network, the bastion hosts will need to know how to deliver mail + to internal hosts. In order for this to work properly, the resolvers + on + the bastion hosts will need to be configured to point to the internal + name servers for DNS resolution. +
++ Queries for internal hostnames will be answered by the internal + servers, and queries for external hostnames will be forwarded back + out to the DNS servers on the bastion hosts. +
++ In order for all this to work properly, internal clients will + need to be configured to query only the internal + name servers for DNS queries. This could also be enforced via + selective + filtering on the network. +
++ If everything has been set properly, Example, Inc.'s + internal clients will now be able to: +
+site1
+ and
+ site2.example.com zones.
+
+ site1.internal and
+ site2.internal domains.
+
+ + Hosts on the Internet will be able to: +
+site1
+ and
+ site2.example.com zones.
+
+ site1 and
+ site2.example.com zones.
+
+ + Here is an example configuration for the setup we just + described above. Note that this is only configuration information; + for information on how to configure your zone files, see the section called “Sample Configurations”. +
+ ++ Internal DNS server config: +
+ +
+
+acl internals { 172.16.72.0/24; 192.168.1.0/24; };
+
+acl externals { bastion-ips-go-here; };
+
+options {
+ ...
+ ...
+ forward only;
+ // forward to external servers
+ forwarders {
+ bastion-ips-go-here;
+ };
+ // sample allow-transfer (no one)
+ allow-transfer { none; };
+ // restrict query access
+ allow-query { internals; externals; };
+ // restrict recursion
+ allow-recursion { internals; };
+ ...
+ ...
+};
+
+// sample master zone
+zone "site1.example.com" {
+ type master;
+ file "m/site1.example.com";
+ // do normal iterative resolution (do not forward)
+ forwarders { };
+ allow-query { internals; externals; };
+ allow-transfer { internals; };
+};
+
+// sample slave zone
+zone "site2.example.com" {
+ type slave;
+ file "s/site2.example.com";
+ masters { 172.16.72.3; };
+ forwarders { };
+ allow-query { internals; externals; };
+ allow-transfer { internals; };
+};
+
+zone "site1.internal" {
+ type master;
+ file "m/site1.internal";
+ forwarders { };
+ allow-query { internals; };
+ allow-transfer { internals; }
+};
+
+zone "site2.internal" {
+ type slave;
+ file "s/site2.internal";
+ masters { 172.16.72.3; };
+ forwarders { };
+ allow-query { internals };
+ allow-transfer { internals; }
+};
+
+
+ + External (bastion host) DNS server config: +
+ +
+acl internals { 172.16.72.0/24; 192.168.1.0/24; };
+
+acl externals { bastion-ips-go-here; };
+
+options {
+ ...
+ ...
+ // sample allow-transfer (no one)
+ allow-transfer { none; };
+ // default query access
+ allow-query { any; };
+ // restrict cache access
+ allow-query-cache { internals; externals; };
+ // restrict recursion
+ allow-recursion { internals; externals; };
+ ...
+ ...
+};
+
+// sample slave zone
+zone "site1.example.com" {
+ type master;
+ file "m/site1.foo.com";
+ allow-transfer { internals; externals; };
+};
+
+zone "site2.example.com" {
+ type slave;
+ file "s/site2.foo.com";
+ masters { another_bastion_host_maybe; };
+ allow-transfer { internals; externals; }
+};
+
+
+
+ In the resolv.conf (or equivalent) on
+ the bastion host(s):
+
+search ... +nameserver 172.16.72.2 +nameserver 172.16.72.3 +nameserver 172.16.72.4 ++ +
+ TSIG (Transaction SIGnatures) is a mechanism for authenticating DNS + messages, originally specified in RFC 2845. It allows DNS messages + to be cryptographically signed using a shared secret. TSIG can + be used in any DNS transaction, as a way to restrict access to + certain server functions (e.g., recursive queries) to authorized + clients when IP-based access control is insufficient or needs to + be overridden, or as a way to ensure message authenticity when it + is critical to the integrity of the server, such as with dynamic + UPDATE messages or zone transfers from a master to a slave server. +
++ This is a guide to setting up TSIG in BIND. + It describes the configuration syntax and the process of creating + TSIG keys. +
++ named supports TSIG for server-to-server + communication, and some of the tools included with + BIND support it for sending messages to + named: +
+-k, -l and
+ -y command line options, or via
+ the key command when running
+ interactively.
+ -k and -y command
+ line options.
+ +
+ +
+ TSIG keys can be generated using the tsig-keygen
+ command; the output of the command is a key directive
+ suitable for inclusion in named.conf. The
+ key name, algorithm and size can be specified by command line parameters;
+ the defaults are "tsig-key", HMAC-SHA256, and 256 bits, respectively.
+
+ Any string which is a valid DNS name can be used as a key name. + For example, a key to be shared between servers called + host1 and host2 could + be called "host1-host2.", and this key could be generated using: +
++ $ tsig-keygen host1-host2. > host1-host2.key ++
+ This key may then be copied to both hosts. The key name and secret + must be identical on both hosts. + (Note: copying a shared secret from one server to another is beyond + the scope of the DNS. A secure transport mechanism should be used: + secure FTP, SSL, ssh, telephone, encrypted email, etc.) +
++ tsig-keygen can also be run as + ddns-confgen, in which case its output includes + additional configuration text for setting up dynamic DNS in + named. See ddns-confgen(8) + for details. +
+
+ For a key shared between servers called
+ host1 and host2,
+ the following could be added to each server's
+ named.conf file:
+
+key "host1-host2." {
+ algorithm hmac-sha256;
+ secret "DAopyf1mhCbFVZw7pgmNPBoLUq8wEUT7UuPoLENP2HY=";
+};
+
+ + (This is the same key generated above using + tsig-keygen.) +
+
+ Since this text contains a secret, it
+ is recommended that either named.conf not be
+ world-readable, or that the key directive
+ be stored in a file which is not world-readable, and which is
+ included in named.conf via the
+ include directive.
+
+ Once a key has been added to named.conf and the
+ server has been restarted or reconfigured, the server can recognize
+ the key. If the server receives a message signed by the
+ key, it will be able to verify the signature. If the signature
+ is valid, the response will be signed using the same key.
+
+ TSIG keys that are known to a server can be listed using the + command rndc tsig-list. +
++ A server sending a request to another server must be told whether + to use a key, and if so, which key to use. +
++ For example, a key may be specified for each server in the + masters statement in the definition of a + slave zone; in this case, all SOA QUERY messages, NOTIFY + messages, and zone transfer requests (AXFR or IXFR) will be + signed using the specified key. Keys may also be specified + in the also-notify statement of a master + or slave zone, causing NOTIFY messages to be signed using + the specified key. +
++ Keys can also be specified in a server + directive. Adding the following on host1, + if the IP address of host2 is 10.1.2.3, would + cause all requests from host1 + to host2, including normal DNS queries, to be + signed using the host1-host2. key: +
+
+server 10.1.2.3 {
+ keys { host1-host2. ;};
+};
+
+ + Multiple keys may be present in the keys + statement, but only the first one is used. As this directive does + not contain secrets, it can be used in a world-readable file. +
++ Requests sent by host2 to host1 + would not be signed, unless a similar + server directive were in host2's + configuration file. +
++ Whenever any server sends a TSIG-signed DNS request, it will expect + the response to be signed with the same key. If a response is not + signed, or if the signature is not valid, the response will be + rejected. +
++ TSIG keys may be specified in ACL definitions and ACL directives + such as allow-query, allow-transfer + and allow-update. + The above key would be denoted in an ACL element as + key host1-host2. +
++ An example of an allow-update directive using + a TSIG key: +
+
+allow-update { !{ !localnets; any; }; key host1-host2. ;};
+
+ + This allows dynamic updates to succeed only if the UPDATE + request comes from an address in localnets, + and if it is signed using the + host1-host2. key. +
++ See the section called “Dynamic Update Policies” for a discussion of + the more flexible update-policy statement. +
++ Processing of TSIG-signed messages can result in several errors: +
++ In all of the above cases, the server will return a response code + of NOTAUTH (not authenticated). +
++ TKEY (Transaction KEY) is a mechanism for automatically negotiating + a shared secret between two hosts, originally specified in RFC 2930. +
++ There are several TKEY "modes" that specify how a key is to be + generated or assigned. BIND 9 implements only + one of these modes: Diffie-Hellman key exchange. Both hosts are + required to have a KEY record with algorithm DH (though this + record is not required to be present in a zone). +
++ The TKEY process is initiated by a client or server by sending + a query of type TKEY to a TKEY-aware server. The query must include + an appropriate KEY record in the additional section, and + must be signed using either TSIG or SIG(0) with a previously + established key. The server's response, if successful, will + contain a TKEY record in its answer section. After this transaction, + both participants will have enough information to calculate a + shared secret using Diffie-Hellman key exchange. The shared secret + can then be used by to sign subsequent transactions between the + two servers. +
++ TSIG keys known by the server, including TKEY-negotiated keys, can + be listed using rndc tsig-list. +
++ TKEY-negotiated keys can be deleted from a server using + rndc tsig-delete. This can also be done via + the TKEY protocol itself, by sending an authenticated TKEY query + specifying the "key deletion" mode. +
+ ++ BIND partially supports DNSSEC SIG(0) + transaction signatures as specified in RFC 2535 and RFC 2931. + SIG(0) uses public/private keys to authenticate messages. Access control + is performed in the same manner as TSIG keys; privileges can be + granted or denied in ACL directives based on the key name. +
++ When a SIG(0) signed message is received, it will only be + verified if the key is known and trusted by the server. The + server will not attempt to recursively fetch or validate the + key. +
++ SIG(0) signing of multiple-message TCP streams is not supported. +
++ The only tool shipped with BIND 9 that + generates SIG(0) signed messages is nsupdate. +
++ Cryptographic authentication of DNS information is possible + through the DNS Security (DNSSEC-bis) extensions, + defined in RFC 4033, RFC 4034, and RFC 4035. + This section describes the creation and use of DNSSEC signed zones. +
+ +
+ In order to set up a DNSSEC secure zone, there are a series
+ of steps which must be followed. BIND
+ 9 ships
+ with several tools
+ that are used in this process, which are explained in more detail
+ below. In all cases, the -h option prints a
+ full list of parameters. Note that the DNSSEC tools require the
+ keyset files to be in the working directory or the
+ directory specified by the -d option, and
+ that the tools shipped with BIND 9.2.x and earlier are not compatible
+ with the current ones.
+
+ There must also be communication with the administrators of
+ the parent and/or child zone to transmit keys. A zone's security
+ status must be indicated by the parent zone for a DNSSEC capable
+ resolver to trust its data. This is done through the presence
+ or absence of a DS record at the
+ delegation
+ point.
+
+ For other servers to trust data in this zone, they must + either be statically configured with this zone's zone key or the + zone key of another zone above this one in the DNS tree. +
+ ++ The dnssec-keygen program is used to + generate keys. +
+ ++ A secure zone must contain one or more zone keys. The + zone keys will sign all other records in the zone, as well as + the zone keys of any secure delegated zones. Zone keys must + have the same name as the zone, a name type of + ZONE, and must be usable for + authentication. + It is recommended that zone keys use a cryptographic algorithm + designated as "mandatory to implement" by the IETF; currently + the only one is RSASHA1. +
+ +
+ The following command will generate a 768-bit RSASHA1 key for
+ the child.example zone:
+
+ dnssec-keygen -a RSASHA1 -b 768 -n ZONE child.example.
+
+ Two output files will be produced:
+ Kchild.example.+005+12345.key and
+ Kchild.example.+005+12345.private
+ (where
+ 12345 is an example of a key tag). The key filenames contain
+ the key name (child.example.),
+ algorithm (3
+ is DSA, 1 is RSAMD5, 5 is RSASHA1, etc.), and the key tag (12345 in
+ this case).
+ The private key (in the .private
+ file) is
+ used to generate signatures, and the public key (in the
+ .key file) is used for signature
+ verification.
+
+ To generate another key with the same properties (but with + a different key tag), repeat the above command. +
+ ++ The dnssec-keyfromlabel program is used + to get a key pair from a crypto hardware and build the key + files. Its usage is similar to dnssec-keygen. +
+ +
+ The public keys should be inserted into the zone file by
+ including the .key files using
+ $INCLUDE statements.
+
+ The dnssec-signzone program is used + to sign a zone. +
+ +
+ Any keyset files corresponding to
+ secure sub-zones should be present. The zone signer will
+ generate NSEC, NSEC3
+ and RRSIG records for the zone, as
+ well as DS for the child zones if
+ '-g' is specified. If '-g'
+ is not specified, then DS RRsets for the secure child
+ zones need to be added manually.
+
+ The following command signs the zone, assuming it is in a
+ file called zone.child.example. By
+ default, all zone keys which have an available private key are
+ used to generate signatures.
+
+ dnssec-signzone -o child.example zone.child.example
+
+ One output file is produced:
+ zone.child.example.signed. This
+ file
+ should be referenced by named.conf
+ as the
+ input file for the zone.
+
dnssec-signzone
+ will also produce a keyset and dsset files and optionally a
+ dlvset file. These are used to provide the parent zone
+ administrators with the DNSKEYs (or their
+ corresponding DS records) that are the
+ secure entry point to the zone.
+
+ To enable named to respond appropriately + to DNS requests from DNSSEC aware clients, + dnssec-enable must be set to yes. + (This is the default setting.) +
+ +
+ To enable named to validate answers from
+ other servers, the dnssec-enable option
+ must be set to yes, and the
+ dnssec-validation options must be set to
+ yes or auto.
+
+ If dnssec-validation is set to
+ auto, then a default
+ trust anchor for the DNS root zone will be used.
+ If it is set to yes, however,
+ then at least one trust anchor must be configured
+ with a trusted-keys or
+ managed-keys statement in
+ named.conf, or DNSSEC validation
+ will not occur. The default setting is
+ yes.
+
+ trusted-keys are copies of DNSKEY RRs + for zones that are used to form the first link in the + cryptographic chain of trust. All keys listed in + trusted-keys (and corresponding zones) + are deemed to exist and only the listed keys will be used + to validated the DNSKEY RRset that they are from. +
+ ++ managed-keys are trusted keys which are + automatically kept up to date via RFC 5011 trust anchor + maintenance. +
+ ++ trusted-keys and + managed-keys are described in more detail + later in this document. +
+ ++ Unlike BIND 8, BIND + 9 does not verify signatures on load, so zone keys for + authoritative zones do not need to be specified in the + configuration file. +
+ ++ After DNSSEC gets established, a typical DNSSEC configuration + will look something like the following. It has one or + more public keys for the root. This allows answers from + outside the organization to be validated. It will also + have several keys for parts of the namespace the organization + controls. These are here to ensure that named + is immune to compromises in the DNSSEC components of the security + of parent zones. +
+ +
+managed-keys {
+ /* Root Key */
+ "." initial-key 257 3 3 "BNY4wrWM1nCfJ+CXd0rVXyYmobt7sEEfK3clRbGaTwS
+ JxrGkxJWoZu6I7PzJu/E9gx4UC1zGAHlXKdE4zYIpRh
+ aBKnvcC2U9mZhkdUpd1Vso/HAdjNe8LmMlnzY3zy2Xy
+ 4klWOADTPzSv9eamj8V18PHGjBLaVtYvk/ln5ZApjYg
+ hf+6fElrmLkdaz MQ2OCnACR817DF4BBa7UR/beDHyp
+ 5iWTXWSi6XmoJLbG9Scqc7l70KDqlvXR3M/lUUVRbke
+ g1IPJSidmK3ZyCllh4XSKbje/45SKucHgnwU5jefMtq
+ 66gKodQj+MiA21AfUVe7u99WzTLzY3qlxDhxYQQ20FQ
+ 97S+LKUTpQcq27R7AT3/V5hRQxScINqwcz4jYqZD2fQ
+ dgxbcDTClU0CRBdiieyLMNzXG3";
+};
+
+trusted-keys {
+ /* Key for our organization's forward zone */
+ example.com. 257 3 5 "AwEAAaxPMcR2x0HbQV4WeZB6oEDX+r0QM6
+ 5KbhTjrW1ZaARmPhEZZe3Y9ifgEuq7vZ/z
+ GZUdEGNWy+JZzus0lUptwgjGwhUS1558Hb
+ 4JKUbbOTcM8pwXlj0EiX3oDFVmjHO444gL
+ kBOUKUf/mC7HvfwYH/Be22GnClrinKJp1O
+ g4ywzO9WglMk7jbfW33gUKvirTHr25GL7S
+ TQUzBb5Usxt8lgnyTUHs1t3JwCY5hKZ6Cq
+ FxmAVZP20igTixin/1LcrgX/KMEGd/biuv
+ F4qJCyduieHukuY3H4XMAcR+xia2nIUPvm
+ /oyWR8BW/hWdzOvnSCThlHf3xiYleDbt/o
+ 1OTQ09A0=";
+
+ /* Key for our reverse zone. */
+ 2.0.192.IN-ADDRPA.NET. 257 3 5 "AQOnS4xn/IgOUpBPJ3bogzwc
+ xOdNax071L18QqZnQQQAVVr+i
+ LhGTnNGp3HoWQLUIzKrJVZ3zg
+ gy3WwNT6kZo6c0tszYqbtvchm
+ gQC8CzKojM/W16i6MG/eafGU3
+ siaOdS0yOI6BgPsw+YZdzlYMa
+ IJGf4M4dyoKIhzdZyQ2bYQrjy
+ Q4LB0lC7aOnsMyYKHHYeRvPxj
+ IQXmdqgOJGq+vsevG06zW+1xg
+ YJh9rCIfnm1GX/KMgxLPG2vXT
+ D/RnLX+D3T3UL7HJYHJhAZD5L
+ 59VvjSPsZJHeDCUyWYrvPZesZ
+ DIRvhDD52SKvbheeTJUm6Ehkz
+ ytNN2SN96QRk8j/iI8ib";
+};
+
+options {
+ ...
+ dnssec-enable yes;
+ dnssec-validation yes;
+};
+
+
+ + None of the keys listed in this example are valid. In particular, + the root key is not valid. +
++ When DNSSEC validation is enabled and properly configured, + the resolver will reject any answers from signed, secure zones + which fail to validate, and will return SERVFAIL to the client. +
+ ++ Responses may fail to validate for any of several reasons, + including missing, expired, or invalid signatures, a key which + does not match the DS RRset in the parent zone, or an insecure + response from a zone which, according to its parent, should have + been secure. +
+ ++ When the validator receives a response from an unsigned zone + that has a signed parent, it must confirm with the parent + that the zone was intentionally left unsigned. It does + this by verifying, via signed and validated NSEC/NSEC3 records, + that the parent zone contains no DS records for the child. +
++ If the validator can prove that the zone + is insecure, then the response is accepted. However, if it + cannot, then it must assume an insecure response to be a + forgery; it rejects the response and logs an error. +
++ The logged error reads "insecurity proof failed" and + "got insecure response; parent indicates it should be secure". + (Prior to BIND 9.7, the logged error was "not insecure". + This referred to the zone, not the response.) +
+As of BIND 9.7.0 it is possible to change a dynamic zone + from insecure to signed and back again. A secure zone can use + either NSEC or NSEC3 chains.
+ +Changing a zone from insecure to secure can be done in two + ways: using a dynamic DNS update, or the + auto-dnssec zone option.
+For either method, you need to configure
+ named so that it can see the
+ K* files which contain the public and private
+ parts of the keys that will be used to sign the zone. These files
+ will have been generated by
+ dnssec-keygen. You can do this by placing them
+ in the key-directory, as specified in
+ named.conf:
+ zone example.net {
+ type master;
+ update-policy local;
+ file "dynamic/example.net/example.net";
+ key-directory "dynamic/example.net";
+ };
+
+ If one KSK and one ZSK DNSKEY key have been generated, this + configuration will cause all records in the zone to be signed + with the ZSK, and the DNSKEY RRset to be signed with the KSK as + well. An NSEC chain will be generated as part of the initial + signing process.
+ +To insert the keys via dynamic update:
++ % nsupdate + > ttl 3600 + > update add example.net DNSKEY 256 3 7 AwEAAZn17pUF0KpbPA2c7Gz76Vb18v0teKT3EyAGfBfL8eQ8al35zz3Y I1m/SAQBxIqMfLtIwqWPdgthsu36azGQAX8= + > update add example.net DNSKEY 257 3 7 AwEAAd/7odU/64o2LGsifbLtQmtO8dFDtTAZXSX2+X3e/UNlq9IHq3Y0 XtC0Iuawl/qkaKVxXe2lo8Ct+dM6UehyCqk= + > send ++
While the update request will complete almost immediately, + the zone will not be completely signed until + named has had time to walk the zone and + generate the NSEC and RRSIG records. The NSEC record at the apex + will be added last, to signal that there is a complete NSEC + chain.
+If you wish to sign using NSEC3 instead of NSEC, you should + add an NSEC3PARAM record to the initial update request. If you + wish the NSEC3 chain to have the OPTOUT bit set, set it in the + flags field of the NSEC3PARAM record.
++ % nsupdate + > ttl 3600 + > update add example.net DNSKEY 256 3 7 AwEAAZn17pUF0KpbPA2c7Gz76Vb18v0teKT3EyAGfBfL8eQ8al35zz3Y I1m/SAQBxIqMfLtIwqWPdgthsu36azGQAX8= + > update add example.net DNSKEY 257 3 7 AwEAAd/7odU/64o2LGsifbLtQmtO8dFDtTAZXSX2+X3e/UNlq9IHq3Y0 XtC0Iuawl/qkaKVxXe2lo8Ct+dM6UehyCqk= + > update add example.net NSEC3PARAM 1 1 100 1234567890 + > send ++
Again, this update request will complete almost + immediately; however, the record won't show up until + named has had a chance to build/remove the + relevant chain. A private type record will be created to record + the state of the operation (see below for more details), and will + be removed once the operation completes.
+While the initial signing and NSEC/NSEC3 chain generation + is happening, other updates are possible as well.
+ +To enable automatic signing, add the
+ auto-dnssec option to the zone statement in
+ named.conf.
+ auto-dnssec has two possible arguments:
+ allow or
+ maintain.
With + auto-dnssec allow, + named can search the key directory for keys + matching the zone, insert them into the zone, and use them to + sign the zone. It will do so only when it receives an + rndc sign <zonename>.
++ + auto-dnssec maintain includes the above + functionality, but will also automatically adjust the zone's + DNSKEY records on schedule according to the keys' timing metadata. + (See dnssec-keygen(8) and + dnssec-settime(8) for more information.) +
+
+ named will periodically search the key directory
+ for keys matching the zone, and if the keys' metadata indicates
+ that any change should be made the zone, such as adding, removing,
+ or revoking a key, then that action will be carried out. By default,
+ the key directory is checked for changes every 60 minutes; this period
+ can be adjusted with the dnssec-loadkeys-interval, up
+ to a maximum of 24 hours. The rndc loadkeys forces
+ named to check for key updates immediately.
+
+ If keys are present in the key directory the first time the zone + is loaded, the zone will be signed immediately, without waiting for an + rndc sign or rndc loadkeys + command. (Those commands can still be used when there are unscheduled + key changes, however.) +
++ When new keys are added to a zone, the TTL is set to match that + of any existing DNSKEY RRset. If there is no existing DNSKEY RRset, + then the TTL will be set to the TTL specified when the key was + created (using the dnssec-keygen -L option), if + any, or to the SOA TTL. +
++ If you wish the zone to be signed using NSEC3 instead of NSEC, + submit an NSEC3PARAM record via dynamic update prior to the + scheduled publication and activation of the keys. If you wish the + NSEC3 chain to have the OPTOUT bit set, set it in the flags field + of the NSEC3PARAM record. The NSEC3PARAM record will not appear in + the zone immediately, but it will be stored for later reference. When + the zone is signed and the NSEC3 chain is completed, the NSEC3PARAM + record will appear in the zone. +
+Using the + auto-dnssec option requires the zone to be + configured to allow dynamic updates, by adding an + allow-update or + update-policy statement to the zone + configuration. If this has not been done, the configuration will + fail.
+ +The state of the signing process is signaled by + private-type records (with a default type value of 65534). When + signing is complete, these records will have a nonzero value for + the final octet (for those records which have a nonzero initial + octet).
+The private type record format: If the first octet is + non-zero then the record indicates that the zone needs to be + signed with the key matching the record, or that all signatures + that match the record should be removed.
++
+
+
+ algorithm (octet 1)
+ key id in network order (octet 2 and 3)
+ removal flag (octet 4)
+ complete flag (octet 5)
+
+
+Only records flagged as "complete" can be removed via + dynamic update. Attempts to remove other private type records + will be silently ignored.
+If the first octet is zero (this is a reserved algorithm + number that should never appear in a DNSKEY record) then the + record indicates changes to the NSEC3 chains are in progress. The + rest of the record contains an NSEC3PARAM record. The flag field + tells what operation to perform based on the flag bits.
++
+
+
+ 0x01 OPTOUT
+ 0x80 CREATE
+ 0x40 REMOVE
+ 0x20 NONSEC
+
+
+ +As with insecure-to-secure conversions, rolling DNSSEC + keys can be done in two ways: using a dynamic DNS update, or the + auto-dnssec zone option.
+ + To perform key rollovers via dynamic update, you need to add
+ the K* files for the new keys so that
+ named can find them. You can then add the new
+ DNSKEY RRs via dynamic update.
+ named will then cause the zone to be signed
+ with the new keys. When the signing is complete the private type
+ records will be updated so that the last octet is non
+ zero.
If this is for a KSK you need to inform the parent and any + trust anchor repositories of the new KSK.
+You should then wait for the maximum TTL in the zone before + removing the old DNSKEY. If it is a KSK that is being updated, + you also need to wait for the DS RRset in the parent to be + updated and its TTL to expire. This ensures that all clients will + be able to verify at least one signature when you remove the old + DNSKEY.
+The old DNSKEY can be removed via UPDATE. Take care to + specify the correct key. + named will clean out any signatures generated + by the old key after the update completes.
+ +When a new key reaches its activation date (as set by
+ dnssec-keygen or dnssec-settime),
+ if the auto-dnssec zone option is set to
+ maintain, named will
+ automatically carry out the key rollover. If the key's algorithm
+ has not previously been used to sign the zone, then the zone will
+ be fully signed as quickly as possible. However, if the new key
+ is replacing an existing key of the same algorithm, then the
+ zone will be re-signed incrementally, with signatures from the
+ old key being replaced with signatures from the new key as their
+ signature validity periods expire. By default, this rollover
+ completes in 30 days, after which it will be safe to remove the
+ old key from the DNSKEY RRset.
Add the new NSEC3PARAM record via dynamic update. When the + new NSEC3 chain has been generated, the NSEC3PARAM flag field + will be zero. At this point you can remove the old NSEC3PARAM + record. The old chain will be removed after the update request + completes.
+ +To do this, you just need to add an NSEC3PARAM record. When + the conversion is complete, the NSEC chain will have been removed + and the NSEC3PARAM record will have a zero flag field. The NSEC3 + chain will be generated before the NSEC chain is + destroyed.
+ +To do this, use nsupdate to + remove all NSEC3PARAM records with a zero flag + field. The NSEC chain will be generated before the NSEC3 chain is + removed.
+ +To convert a signed zone to unsigned using dynamic DNS, + delete all the DNSKEY records from the zone apex using + nsupdate. All signatures, NSEC or NSEC3 chains, + and associated NSEC3PARAM records will be removed automatically. + This will take place after the update request completes.
+ This requires the
+ dnssec-secure-to-insecure option to be set to
+ yes in
+ named.conf.
In addition, if the auto-dnssec maintain + zone statement is used, it should be removed or changed to + allow instead (or it will re-sign). +
+ +In any secure zone which supports dynamic updates, named + will periodically re-sign RRsets which have not been re-signed as + a result of some update action. The signature lifetimes will be + adjusted so as to spread the re-sign load over time rather than + all at once.
+ ++ named only supports creating new NSEC3 chains + where all the NSEC3 records in the zone have the same OPTOUT + state. + named supports UPDATES to zones where the NSEC3 + records in the chain have mixed OPTOUT state. + named does not support changing the OPTOUT + state of an individual NSEC3 record, the entire chain needs to be + changed if the OPTOUT state of an individual NSEC3 needs to be + changed.
+BIND 9.7.0 introduces support for RFC 5011, dynamic trust + anchor management. Using this feature allows + named to keep track of changes to critical + DNSSEC keys without any need for the operator to make changes to + configuration files.
+To configure a validating resolver to use RFC 5011 to + maintain a trust anchor, configure the trust anchor using a + managed-keys statement. Information about + this can be found in + the section called “managed-keys Statement Definition + and Usage”.
+ +To set up an authoritative zone for RFC 5011 trust anchor + maintenance, generate two (or more) key signing keys (KSKs) for + the zone. Sign the zone with one of them; this is the "active" + KSK. All KSKs which do not sign the zone are "stand-by" + keys.
+Any validating resolver which is configured to use the + active KSK as an RFC 5011-managed trust anchor will take note + of the stand-by KSKs in the zone's DNSKEY RRset, and store them + for future reference. The resolver will recheck the zone + periodically, and after 30 days, if the new key is still there, + then the key will be accepted by the resolver as a valid trust + anchor for the zone. Any time after this 30-day acceptance + timer has completed, the active KSK can be revoked, and the + zone can be "rolled over" to the newly accepted key.
+The easiest way to place a stand-by key in a zone is to + use the "smart signing" features of + dnssec-keygen and + dnssec-signzone. If a key with a publication + date in the past, but an activation date which is unset or in + the future, " + dnssec-signzone -S" will include the DNSKEY + record in the zone, but will not sign with it:
++$+dnssec-keygen -K keys -f KSK -P now -A now+2y example.net+$dnssec-signzone -S -K keys example.net+
To revoke a key, the new command
+ dnssec-revoke has been added. This adds the
+ REVOKED bit to the key flags and re-generates the
+ K*.key and
+ K*.private files.
After revoking the active key, the zone must be signed + with both the revoked KSK and the new active KSK. (Smart + signing takes care of this automatically.)
+Once a key has been revoked and used to sign the DNSKEY + RRset in which it appears, that key will never again be + accepted as a valid trust anchor by the resolver. However, + validation can proceed using the new active key (which had been + accepted by the resolver when it was a stand-by key).
+See RFC 5011 for more details on key rollover + scenarios.
+When a key has been revoked, its key ID changes,
+ increasing by 128, and wrapping around at 65535. So, for
+ example, the key "Kexample.com.+005+10000" becomes
+ "Kexample.com.+005+10128".
If two keys have IDs exactly 128 apart, and one is + revoked, then the two key IDs will collide, causing several + problems. To prevent this, + dnssec-keygen will not generate a new key if + another key is present which may collide. This checking will + only occur if the new keys are written to the same directory + which holds all other keys in use for that zone.
+Older versions of BIND 9 did not have this precaution. + Exercise caution if using key revocation on keys that were + generated by previous releases, or if using keys stored in + multiple directories or on multiple machines.
+It is expected that a future release of BIND 9 will + address this problem in a different way, by storing revoked + keys with their original unrevoked key IDs.
++ PKCS#11 (Public Key Cryptography Standard #11) defines a + platform-independent API for the control of hardware security + modules (HSMs) and other cryptographic support devices. +
++ BIND 9 is known to work with three HSMs: The AEP Keyper, which has + been tested with Debian Linux, Solaris x86 and Windows Server 2003; + the Thales nShield, tested with Debian Linux; and the Sun SCA 6000 + cryptographic acceleration board, tested with Solaris x86. In + addition, BIND can be used with all current versions of SoftHSM, + a software-based HSM simulator library produced by the OpenDNSSEC + project. +
++ PKCS#11 makes use of a "provider library": a dynamically loadable + library which provides a low-level PKCS#11 interface to drive the HSM + hardware. The PKCS#11 provider library comes from the HSM vendor, and + it is specific to the HSM to be controlled. +
++ There are two available mechanisms for PKCS#11 support in BIND 9: + OpenSSL-based PKCS#11 and native PKCS#11. When using the first + mechanism, BIND uses a modified version of OpenSSL, which loads + the provider library and operates the HSM indirectly; any + cryptographic operations not supported by the HSM can be carried + out by OpenSSL instead. The second mechanism enables BIND to bypass + OpenSSL completely; BIND loads the provider library itself, and uses + the PKCS#11 API to drive the HSM directly. +
++ See the documentation provided by your HSM vendor for + information about installing, initializing, testing and + troubleshooting the HSM. +
++ Native PKCS#11 mode will only work with an HSM capable of carrying + out every cryptographic operation BIND 9 may + need. The HSM's provider library must have a complete implementation + of the PKCS#11 API, so that all these functions are accessible. As of + this writing, only the Thales nShield HSM and SoftHSMv2 can be used + in this fashion. For other HSMs, including the AEP Keyper, Sun SCA + 6000 and older versions of SoftHSM, use OpenSSL-based PKCS#11. + (Note: Eventually, when more HSMs become capable of supporting + native PKCS#11, it is expected that OpenSSL-based PKCS#11 will + be deprecated.) +
++ To build BIND with native PKCS#11, configure as follows: +
++$+cd bind9+$./configure --enable-native-pkcs11 \ + --with-pkcs11=+provider-library-path
+ This will cause all BIND tools, including named
+ and the dnssec-* and pkcs11-*
+ tools, to use the PKCS#11 provider library specified in
+ provider-library-path for cryptography.
+ (The provider library path can be overridden using the
+ -E in named and the
+ dnssec-* tools, or the -m in
+ the pkcs11-* tools.)
+
+ SoftHSMv2, the latest development version of SoftHSM, is available + from + + https://github.com/opendnssec/SoftHSMv2 + . + It is a software library developed by the OpenDNSSEC project + ( + http://www.opendnssec.org + ) + which provides a PKCS#11 interface to a virtual HSM, implemented in + the form of a SQLite3 database on the local filesystem. It provides + less security than a true HSM, but it allows you to experiment with + native PKCS#11 when an HSM is not available. SoftHSMv2 can be + configured to use either OpenSSL or the Botan library to perform + cryptographic functions, but when using it for native PKCS#11 in + BIND, OpenSSL is required. +
+
+ By default, the SoftHSMv2 configuration file is
+ prefix/etc/softhsm2.conf (where
+ prefix is configured at compile time).
+ This location can be overridden by the SOFTHSM2_CONF environment
+ variable. The SoftHSMv2 cryptographic store must be installed and
+ initialized before using it with BIND.
+
+$+cd SoftHSMv2+$configure --with-crypto-backend=openssl --prefix=/opt/pkcs11/usr --enable-gost+$make+$make install+$/opt/pkcs11/usr/bin/softhsm-util --init-token 0 --slot 0 --label softhsmv2+
+ OpenSSL-based PKCS#11 mode uses a modified version of the + OpenSSL library; stock OpenSSL does not fully support PKCS#11. + ISC provides a patch to OpenSSL to correct this. This patch is + based on work originally done by the OpenSolaris project; it has been + modified by ISC to provide new features such as PIN management and + key-by-reference. +
++ There are two "flavors" of PKCS#11 support provided by + the patched OpenSSL, one of which must be chosen at + configuration time. The correct choice depends on the HSM + hardware: +
++ Use 'crypto-accelerator' with HSMs that have hardware + cryptographic acceleration features, such as the SCA 6000 + board. This causes OpenSSL to run all supported + cryptographic operations in the HSM. +
++ Use 'sign-only' with HSMs that are designed to + function primarily as secure key storage devices, but lack + hardware acceleration. These devices are highly secure, but + are not necessarily any faster at cryptography than the + system CPU — often, they are slower. It is therefore + most efficient to use them only for those cryptographic + functions that require access to the secured private key, + such as zone signing, and to use the system CPU for all + other computationally-intensive operations. The AEP Keyper + is an example of such a device. +
++ The modified OpenSSL code is included in the BIND 9 release, + in the form of a context diff against the latest versions of + OpenSSL. OpenSSL 0.9.8, 1.0.0, 1.0.1 and 1.0.2 are supported; + there are separate diffs for each version. In the examples to + follow, we use OpenSSL 0.9.8, but the same methods work with + OpenSSL 1.0.0 through 1.0.2. +
++ The OpenSSL patches as of this writing (January 2016) + support versions 0.9.8zh, 1.0.0t, 1.0.1q and 1.0.2f. + ISC will provide updated patches as new versions of OpenSSL + are released. The version number in the following examples + is expected to change. +
++ Before building BIND 9 with PKCS#11 support, it will be + necessary to build OpenSSL with the patch in place, and configure + it with the path to your HSM's PKCS#11 provider library. +
+
+$ wget http://www.openssl.org/source/openssl-0.9.8zc.tar.gz
+
+ Extract the tarball:
+
+$ tar zxf openssl-0.9.8zc.tar.gz
+
+ Apply the patch from the BIND 9 release:
+
+$ patch -p1 -d openssl-0.9.8zc \
+ < bind9/bin/pkcs11/openssl-0.9.8zc-patch
+
+ + The patch file may not be compatible with the + "patch" utility on all operating systems. You may need to + install GNU patch. +
++ When building OpenSSL, place it in a non-standard + location so that it does not interfere with OpenSSL libraries + elsewhere on the system. In the following examples, we choose + to install into "/opt/pkcs11/usr". We will use this location + when we configure BIND 9. +
++ Later, when building BIND 9, the location of the custom-built + OpenSSL library will need to be specified via configure. +
++ The AEP Keyper is a highly secure key storage device, + but does not provide hardware cryptographic acceleration. It + can carry out cryptographic operations, but it is probably + slower than your system's CPU. Therefore, we choose the + 'sign-only' flavor when building OpenSSL. +
++ The Keyper-specific PKCS#11 provider library is + delivered with the Keyper software. In this example, we place + it /opt/pkcs11/usr/lib: +
+
+$ cp pkcs11.GCC4.0.2.so.4.05 /opt/pkcs11/usr/lib/libpkcs11.so
+
+ + The Keyper library requires threads, so we + must specify -pthread. +
++$+cd openssl-0.9.8zc+$./Configure linux-x86_64 -pthread \ + --pk11-libname=/opt/pkcs11/usr/lib/libpkcs11.so \ + --pk11-flavor=sign-only \ + --prefix=/opt/pkcs11/usr+
+ After configuring, run "make" + and "make test". If "make + test" fails with "pthread_atfork() not found", you forgot to + add the -pthread above. +
++ The SCA-6000 PKCS#11 provider is installed as a system + library, libpkcs11. It is a true crypto accelerator, up to 4 + times faster than any CPU, so the flavor shall be + 'crypto-accelerator'. +
++ In this example, we are building on Solaris x86 on an + AMD64 system. +
++$+cd openssl-0.9.8zc+$./Configure solaris64-x86_64-cc \ + --pk11-libname=/usr/lib/64/libpkcs11.so \ + --pk11-flavor=crypto-accelerator \ + --prefix=/opt/pkcs11/usr+
+ (For a 32-bit build, use "solaris-x86-cc" and /usr/lib/libpkcs11.so.) +
++ After configuring, run + make and + make test. +
++ SoftHSM (version 1) is a software library developed by the + OpenDNSSEC project + ( + http://www.opendnssec.org + ) + which provides a + PKCS#11 interface to a virtual HSM, implemented in the form of + a SQLite3 database on the local filesystem. SoftHSM uses + the Botan library to perform cryptographic functions. Though + less secure than a true HSM, it can allow you to experiment + with PKCS#11 when an HSM is not available. +
++ The SoftHSM cryptographic store must be installed and + initialized before using it with OpenSSL, and the SOFTHSM_CONF + environment variable must always point to the SoftHSM configuration + file: +
++$+cd softhsm-1.3.7+$configure --prefix=/opt/pkcs11/usr+$make+$make install+$export SOFTHSM_CONF=/opt/pkcs11/softhsm.conf+$echo "0:/opt/pkcs11/softhsm.db" > $SOFTHSM_CONF+$/opt/pkcs11/usr/bin/softhsm --init-token 0 --slot 0 --label softhsm+
+ SoftHSM can perform all cryptographic operations, but + since it only uses your system CPU, there is no advantage to using + it for anything but signing. Therefore, we choose the 'sign-only' + flavor when building OpenSSL. +
++$+cd openssl-0.9.8zc+$./Configure linux-x86_64 -pthread \ + --pk11-libname=/opt/pkcs11/usr/lib/libsofthsm.so \ + --pk11-flavor=sign-only \ + --prefix=/opt/pkcs11/usr+
+ After configuring, run "make" + and "make test". +
++ Once you have built OpenSSL, run + "apps/openssl engine pkcs11" to confirm + that PKCS#11 support was compiled in correctly. The output + should be one of the following lines, depending on the flavor + selected: +
++ (pkcs11) PKCS #11 engine support (sign only) ++
Or:
++ (pkcs11) PKCS #11 engine support (crypto accelerator) ++
+ Next, run
+ "apps/openssl engine pkcs11 -t". This will
+ attempt to initialize the PKCS#11 engine. If it is able to
+ do so successfully, it will report
+ “[ available ]”.
+
+ If the output is correct, run
+ "make install" which will install the
+ modified OpenSSL suite to /opt/pkcs11/usr.
+
+ To link with the PKCS#11 provider, threads must be + enabled in the BIND 9 build. +
++$+cd ../bind9+$./configure --enable-threads \ + --with-openssl=/opt/pkcs11/usr \ + --with-pkcs11=/opt/pkcs11/usr/lib/libpkcs11.so+
+ To link with the PKCS#11 provider, threads must be + enabled in the BIND 9 build. +
++$+cd ../bind9+$./configure CC="cc -xarch=amd64" --enable-threads \ + --with-openssl=/opt/pkcs11/usr \ + --with-pkcs11=/usr/lib/64/libpkcs11.so+
(For a 32-bit build, omit CC="cc -xarch=amd64".)
++ If configure complains about OpenSSL not working, you + may have a 32/64-bit architecture mismatch. Or, you may have + incorrectly specified the path to OpenSSL (it should be the + same as the --prefix argument to the OpenSSL + Configure). +
++$+cd ../bind9+$./configure --enable-threads \ + --with-openssl=/opt/pkcs11/usr \ + --with-pkcs11=/opt/pkcs11/usr/lib/libsofthsm.so+
+ After configuring, run + "make", + "make test" and + "make install". +
++ (Note: If "make test" fails in the "pkcs11" system test, you may + have forgotten to set the SOFTHSM_CONF environment variable.) +
++ BIND 9 includes a minimal set of tools to operate the + HSM, including + pkcs11-keygen to generate a new key pair + within the HSM, + pkcs11-list to list objects currently + available, + pkcs11-destroy to remove objects, and + pkcs11-tokens to list available tokens. +
++ In UNIX/Linux builds, these tools are built only if BIND + 9 is configured with the --with-pkcs11 option. (Note: If + --with-pkcs11 is set to "yes", rather than to the path of the + PKCS#11 provider, then the tools will be built but the + provider will be left undefined. Use the -m option or the + PKCS11_PROVIDER environment variable to specify the path to the + provider.) +
++ For OpenSSL-based PKCS#11, we must first set up the runtime + environment so the OpenSSL and PKCS#11 libraries can be loaded: +
+
+$ export LD_LIBRARY_PATH=/opt/pkcs11/usr/lib:${LD_LIBRARY_PATH}
+
+
+ This causes named and other binaries to load
+ the OpenSSL library from /opt/pkcs11/usr/lib
+ rather than from the default location. This step is not necessary
+ when using native PKCS#11.
+
+ Some HSMs require other environment variables to be set.
+ For example, when operating an AEP Keyper, it is necessary to
+ specify the location of the "machine" file, which stores
+ information about the Keyper for use by the provider
+ library. If the machine file is in
+ /opt/Keyper/PKCS11Provider/machine,
+ use:
+
+$ export KEYPER_LIBRARY_PATH=/opt/Keyper/PKCS11Provider
+
+ + Such environment variables must be set whenever running + any tool that uses the HSM, including + pkcs11-keygen, + pkcs11-list, + pkcs11-destroy, + dnssec-keyfromlabel, + dnssec-signzone, + dnssec-keygen, and + named. +
++ We can now create and use keys in the HSM. In this case, + we will create a 2048 bit key and give it the label + "sample-ksk": +
+
+$ pkcs11-keygen -b 2048 -l sample-ksk
+
+ To confirm that the key exists:
+
+$ pkcs11-list
+Enter PIN:
+object[0]: handle 2147483658 class 3 label[8] 'sample-ksk' id[0]
+object[1]: handle 2147483657 class 2 label[8] 'sample-ksk' id[0]
+
+ + Before using this key to sign a zone, we must create a + pair of BIND 9 key files. The "dnssec-keyfromlabel" utility + does this. In this case, we will be using the HSM key + "sample-ksk" as the key-signing key for "example.net": +
+
+$ dnssec-keyfromlabel -l sample-ksk -f KSK example.net
+
+ + The resulting K*.key and K*.private files can now be used + to sign the zone. Unlike normal K* files, which contain both + public and private key data, these files will contain only the + public key data, plus an identifier for the private key which + remains stored within the HSM. Signing with the private key takes + place inside the HSM. +
++ If you wish to generate a second key in the HSM for use + as a zone-signing key, follow the same procedure above, using a + different keylabel, a smaller key size, and omitting "-f KSK" + from the dnssec-keyfromlabel arguments: +
++ (Note: When using OpenSSL-based PKCS#11 the label is an arbitrary + string which identifies the key. With native PKCS#11, the label is + a PKCS#11 URI string which may include other details about the key + and the HSM, including its PIN. See + dnssec-keyfromlabel(8) for details.) +
++$+pkcs11-keygen -b 1024 -l sample-zsk+$dnssec-keyfromlabel -l sample-zsk example.net+
+ Alternatively, you may prefer to generate a conventional + on-disk key, using dnssec-keygen: +
+
+$ dnssec-keygen example.net
+
+ + This provides less security than an HSM key, but since + HSMs can be slow or cumbersome to use for security reasons, it + may be more efficient to reserve HSM keys for use in the less + frequent key-signing operation. The zone-signing key can be + rolled more frequently, if you wish, to compensate for a + reduction in key security. (Note: When using native PKCS#11, + there is no speed advantage to using on-disk keys, as cryptographic + operations will be done by the HSM regardless.) +
+
+ Now you can sign the zone. (Note: If not using the -S
+ option to dnssec-signzone, it will be
+ necessary to add the contents of both K*.key
+ files to the zone master file before signing it.)
+
+$ dnssec-signzone -S example.net
+Enter PIN:
+Verifying the zone using the following algorithms:
+NSEC3RSASHA1.
+Zone signing complete:
+Algorithm: NSEC3RSASHA1: ZSKs: 1, KSKs: 1 active, 0 revoked, 0 stand-by
+example.net.signed
+
+ + When using OpenSSL-based PKCS#11, the "engine" to be used by + OpenSSL can be specified in named and all of + the BIND dnssec-* tools by using the "-E + <engine>" command line option. If BIND 9 is built with + the --with-pkcs11 option, this option defaults to "pkcs11". + Specifying the engine will generally not be necessary unless + for some reason you wish to use a different OpenSSL + engine. +
++ If you wish to disable use of the "pkcs11" engine — + for troubleshooting purposes, or because the HSM is unavailable + — set the engine to the empty string. For example: +
+
+$ dnssec-signzone -E '' -S example.net
+
+ + This causes + dnssec-signzone to run as if it were compiled + without the --with-pkcs11 option. +
++ When built with native PKCS#11 mode, the "engine" option has a + different meaning: it specifies the path to the PKCS#11 provider + library. This may be useful when testing a new provider library. +
+
+ If you want named to dynamically re-sign zones
+ using HSM keys, and/or to to sign new records inserted via nsupdate,
+ then named must have access to the HSM PIN. In OpenSSL-based PKCS#11,
+ this is accomplished by placing the PIN into the openssl.cnf file
+ (in the above examples,
+ /opt/pkcs11/usr/ssl/openssl.cnf).
+
+ The location of the openssl.cnf file can be overridden by + setting the OPENSSL_CONF environment variable before running + named. +
+Sample openssl.cnf:
+
+ openssl_conf = openssl_def
+ [ openssl_def ]
+ engines = engine_section
+ [ engine_section ]
+ pkcs11 = pkcs11_section
+ [ pkcs11_section ]
+ PIN = <PLACE PIN HERE>
+
+ + This will also allow the dnssec-* tools to access the HSM + without PIN entry. (The pkcs11-* tools access the HSM directly, + not via OpenSSL, so a PIN will still be required to use + them.) +
+
+ In native PKCS#11 mode, the PIN can be provided in a file specified
+ as an attribute of the key's label. For example, if a key had the label
+ pkcs11:object=local-zsk;pin-source=/etc/hsmpin,
+ then the PIN would be read from the file
+ /etc/hsmpin.
+
+ Placing the HSM's PIN in a text file in this manner may reduce the + security advantage of using an HSM. Be sure this is what you want to + do before configuring the system in this way. +
++ DLZ (Dynamically Loadable Zones) is an extension to BIND 9 that allows + zone data to be retrieved directly from an external database. There is + no required format or schema. DLZ drivers exist for several different + database backends including PostgreSQL, MySQL, and LDAP and can be + written for any other. +
+
+ Historically, DLZ drivers had to be statically linked with the named
+ binary and were turned on via a configure option at compile time (for
+ example, "configure --with-dlz-ldap").
+ Currently, the drivers provided in the BIND 9 tarball in
+ contrib/dlz/drivers are still linked this
+ way.
+
+ In BIND 9.8 and higher, it is possible to link some DLZ modules
+ dynamically at runtime, via the DLZ "dlopen" driver, which acts as a
+ generic wrapper around a shared object implementing the DLZ API. The
+ "dlopen" driver is linked into named by default, so configure options
+ are no longer necessary when using these dynamically linkable drivers,
+ but are still needed for the older drivers in
+ contrib/dlz/drivers.
+
+ When the DLZ module provides data to named, it does so in text format. + The response is converted to DNS wire format by named. This + conversion, and the lack of any internal caching, places significant + limits on the query performance of DLZ modules. Consequently, DLZ is + not recommended for use on high-volume servers. However, it can be + used in a hidden master configuration, with slaves retrieving zone + updates via AXFR. (Note, however, that DLZ has no built-in support for + DNS notify; slaves are not automatically informed of changes to the + zones in the database.) +
+ +
+ A DLZ database is configured with a dlz
+ statement in named.conf:
+
+ dlz example {
+ database "dlopen driver.so args";
+ search yes;
+ };
+
+
+ This specifies a DLZ module to search when answering queries; the
+ module is implemented in driver.so and is
+ loaded at runtime by the dlopen DLZ driver. Multiple
+ dlz statements can be specified; when
+ answering a query, all DLZ modules with search
+ set to yes will be queried to find out if
+ they contain an answer for the query name; the best available
+ answer will be returned to the client.
+
+ The search option in the above example can be
+ omitted, because yes is the default value.
+
+ If search is set to no, then
+ this DLZ module is not searched for the best
+ match when a query is received. Instead, zones in this DLZ must be
+ separately specified in a zone statement. This allows you to
+ configure a zone normally using standard zone option semantics,
+ but specify a different database back-end for storage of the
+ zone's data. For example, to implement NXDOMAIN redirection using
+ a DLZ module for back-end storage of redirection rules:
+
+ dlz other {
+ database "dlopen driver.so args";
+ search no;
+ };
+
+ zone "." {
+ type redirect;
+ dlz other;
+ };
+
+
+ For guidance in implementation of DLZ modules, the directory
+ contrib/dlz/example contains a basic
+ dynamically-linkable DLZ module--i.e., one which can be
+ loaded at runtime by the "dlopen" DLZ driver.
+ The example sets up a single zone, whose name is passed
+ to the module as an argument in the dlz
+ statement:
+
+ dlz other {
+ database "dlopen driver.so example.nil";
+ };
+
+ + In the above example, the module is configured to create a zone + "example.nil", which can answer queries and AXFR requests, and + accept DDNS updates. At runtime, prior to any updates, the zone + contains an SOA, NS, and a single A record at the apex: +
++ example.nil. 3600 IN SOA example.nil. hostmaster.example.nil. ( + 123 900 600 86400 3600 + ) + example.nil. 3600 IN NS example.nil. + example.nil. 1800 IN A 10.53.0.1 ++
+ The sample driver is capable of retrieving information about the
+ querying client, and altering its response on the basis of this
+ information. To demonstrate this feature, the example driver
+ responds to queries for "source-addr.zonename>/TXT"
+ with the source address of the query. Note, however, that this
+ record will *not* be included in AXFR or ANY responses. Normally,
+ this feature would be used to alter responses in some other fashion,
+ e.g., by providing different address records for a particular name
+ depending on the network from which the query arrived.
+
+ Documentation of the DLZ module API can be found in
+ contrib/dlz/example/README. This directory also
+ contains the header file dlz_minimal.h, which
+ defines the API and should be included by any dynamically-linkable
+ DLZ module.
+
+ DynDB is an extension to BIND 9 which, like DLZ + (see the section called “DLZ (Dynamically Loadable Zones)”), allows zone data to be + retrieved from an external database. Unlike DLZ, a DynDB module + provides a full-featured BIND zone database interface. Where + DLZ translates DNS queries into real-time database lookups, + resulting in relatively poor query performance, and is unable + to handle DNSSEC-signed data due to its limited API, a DynDB + module can pre-load an in-memory database from the external + data source, providing the same performance and functionality + as zones served natively by BIND. +
++ A DynDB module supporting LDAP has been created by Red Hat + and is available from + https://fedorahosted.org/bind-dyndb-ldap/. +
+
+ A sample DynDB module for testing and developer guidance
+ is included with the BIND source code, in the directory
+ bin/tests/system/dyndb/driver.
+
+ A DynDB database is configured with a dyndb
+ statement in named.conf:
+
+ dyndb example "driver.so" {
+ parameters
+ };
+
+
+ The file driver.so is a DynDB module which
+ implements the full DNS database API. Multiple
+ dyndb statements can be specified, to load
+ different drivers or multiple instances of the same driver.
+ Zones provided by a DynDB module are added to the view's zone
+ table, and are treated as normal authoritative zones when BIND
+ is responding to queries. Zone configuration is handled internally
+ by the DynDB module.
+
+ The parameters are passed as an opaque
+ string to the DynDB module's initialization routine. Configuration
+ syntax will differ depending on the driver.
+
+ For guidance in implementation of DynDB modules, the directory
+ bin/tests/system/dyndb/driver.
+ contains a basic DynDB module.
+ The example sets up two zones, whose names are passed
+ to the module as arguments in the dyndb
+ statement:
+
+ dyndb sample "sample.so" { example.nil. arpa. };
+
+ + In the above example, the module is configured to create a zone + "example.nil", which can answer queries and AXFR requests, and + accept DDNS updates. At runtime, prior to any updates, the zone + contains an SOA, NS, and a single A record at the apex: +
++ example.nil. 86400 IN SOA example.nil. example.nil. ( + 0 28800 7200 604800 86400 + ) + example.nil. 86400 IN NS example.nil. + example.nil. 86400 IN A 127.0.0.1 ++
+ When the zone is updated dynamically, the DynDB module will determine + whether the updated RR is an address (i.e., type A or AAAA) and if + so, it will automatically update the corresponding PTR record in a + reverse zone. (Updates are not stored permanently; all updates are + lost when the server is restarted.) +
++ A "catalog zone" is a special DNS zone that contains a list of + other zones to be served, along with their configuration parameters. + Zones listed in a catalog zone are called "member zones". + When a catalog zone is loaded or transferred to a slave server + which supports this functionality, the slave server will create + the member zones automatically. When the catalog zone is updated + (for example, to add or delete member zones, or change + their configuration parameters) those changes are immediately put + into effect. Because the catalog zone is a normal DNS zone, these + configuration changes can be propagated using the standard AXFR/IXFR + zone transfer mechanism. +
++ Catalog zones' format and behavior are specified as an internet draft + for interoperability among DNS implementations. As of this release, the + latest revision of the DNS catalog zones draft can be found here: + https://datatracker.ietf.org/doc/draft-muks-dnsop-dns-catalog-zones/ +
+ +
+ Normally, if a zone is to be served by a slave server, the
+ named.conf file on the server must list the
+ zone, or the zone must be added using rndc addzone.
+ In environments with a large number of slave servers and/or where
+ the zones being served are changing frequently, the overhead involved
+ in maintaining consistent zone configuration on all the slave
+ servers can be significant.
+
+ A catalog zone is a way to ease this administrative burden. It is a + DNS zone that lists member zones that should be served by slave servers. + When a slave server receives an update to the catalog zone, it adds, + removes, or reconfigures member zones based on the data received. +
+
+ To use a catalog zone, it must first be set up as a normal zone on
+ the master and the on slave servers that will be configured to use
+ it. It must also be added to a catalog-zones list
+ in the options or view statement
+ in named.conf. (This is comparable to the way
+ a policy zone is configured as a normal zone and also listed in
+ a response-policy statement.)
+
+ To use the catalog zone feature to serve a new member zone: +
+
+ Set up the the member zone to be served on the master as normal.
+ This could be done by editing named.conf,
+ or by running rndc addzone.
+
+ Add an entry to the catalog zone for the new member zone. + This could be done by editing the catalog zone's master file + and running rndc reload, or by updating + the zone using nsupdate. +
+
+ The change to the catalog zone will be propagated from the master to all
+ slaves using the normal AXFR/IXFR mechanism. When the slave receives the
+ update to the catalog zone, it will detect the entry for the new member
+ zone, create an instance of of that zone on the slave server, and point
+ that instance to the masters specified in the catalog
+ zone data. The newly created member zone is a normal slave zone, so
+ BIND will immediately initiate a transfer of zone contents from the
+ master. Once complete, the slave will start serving the member zone.
+
+ Removing a member zone from a slave server requires nothing more than + deleting the member zone's entry in the catalog zone. The change to the + catalog cone is propagated to the slave server using the normal AXFR/IXFR + transfer mechanism. The slave server, on processing the update, will + notice that the member zone has been removed. It will stop serving the + zone and remove it from its list of configured zones. (Removing the + member zone from the master server has to be done in the normal way, + by editing the configuration file or running + rndc delzone.) +
+
+ Catalog zones are configured with a catalog-zones
+ statement in the options or view
+ section of named.conf. For example,
+
+catalog-zones {
+ zone "catalog.example"
+ default-masters { 10.53.0.1; }
+ in-memory no
+ zone-directory "catzones"
+ min-update-interval 10;
+};
+
+
+ This statement specifies that the zone
+ catalog.example is a catalog zone. This zone must be
+ properly configured in the same view. In most configurations, it would
+ be a slave zone.
+
+ The options following the zone name are not required, and may be + specified in any order: +
+
+ The default-masters option defines the default masters
+ for member zones listed in a catalog zone. This can be overridden by
+ options within a catalog zone. If no such options are included, then
+ member zones will transfer their contents from the servers listed in
+ this option.
+
+ The in-memory option, if set to yes,
+ causes member zones to be stored only in memory. This is functionally
+ equivalent to configuring a slave zone without a file.
+ option. The default is no; member zones' content
+ will be stored locally in a file whose name is automatically generated
+ from the view name, catalog zone name, and member zone name.
+
+ The zone-directory option causes local copies of
+ member zones' master files (if in-memory is not set
+ to yes) to be stored in the specified directory.
+ The default is to store zone files in the server's working directory.
+ A non-absolute pathname in zone-directory is
+ assumed to be relative to the working directory.
+
+ The min-update-interval option sets the minimum
+ interval between processing of updates to catalog zones, in seconds.
+ If an update to a catalog zone (for example, via IXFR) happens less
+ than min-update-interval seconds after the most
+ recent update, then the changes will not be carried out until this
+ interval has elapsed. The default is 5 seconds.
+
+ Catalog zones are defined on a per-view basis. Configuring a non-empty
+ catalog-zones statement in a view will automatically
+ turn on allow-new-zones for that view. (Note: this
+ means rndc addzone and rndc delzone
+ will also work in any view that supports catalog zones.)
+
+ A catalog zone is a regular DNS zone; therefore, it has to have a
+ single SOA and at least one NS
+ record.
+
+ A record stating the version of the catalog zone format is + also required. If the version number listed is not supported by + the server, then a catalog zone may not be used by that server. +
++catalog.example. IN SOA . . 2016022901 900 600 86400 1 +catalog.example. IN NS nsexample. +version.catalog.example. IN TXT "1" ++
+ Note that this record must have the domain name
+ version.catalog-zone-name. This illustrates
+ how the meaning of data stored in a catalog zone is indicated by the
+ the domain name label immediately before the catalog zone domain.
+
+ Catalog zone options can be set either globally for the whole catalog + zone or for a single member zone. Global options override the settings + in the configuration file and member zone options override global + options. +
++ Global options are set at the apex of the catalog zone, e.g.: +
++ masters.catalog.example. IN AAAA 2001:db8::1 ++
BIND currently supports the following options:
+A simple masters definition:
+ masters.catalog.example. IN A 192.0.2.1 ++
+ This option defines a master server for the member zones - it + can be either an A or AAAA record. If multiple masters are set the + order in which they are used is random. +
+A masters with a TSIG key defined:
+ label.masters.catalog.example. IN A 192.0.2.2 + label.masters.catalog.example. IN TXT "tsig_key_name" ++
+ This option defines a master server for the member zone with a TSIG
+ key set. The TSIG key must be configured in the configuration file.
+ label can be any valid DNS label.
+
allow-query and
+ allow-transfer ACLs:
+ allow-query.catalog.example. IN APL 1:10.0.0.1/24 + allow-transfer.catalog.example. IN APL !1:10.0.0.1/32 1:10.0.0.0/24 ++
+ These options are the equivalents of allow-query
+ and allow-transfer in a zone declaration in the
+ named.conf configuration file. The ACL is
+ processed in order - if there's no match to any rule the default
+ policy is to deny access. For the syntax of the APL RR see RFC
+ 3123
+
+ A member zone is added by including a PTR
+ resource record in the zones sub-domain of the
+ catalog zone. The record label is a SHA-1 hash
+ of the member zone name in wire format. The target of the PTR
+ record is the member zone name. For example, to add the member
+ zone domain.example:
+
+5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN PTR domain.example. ++
+ The hash is necessary to identify options for a specific member + zone. The member zone-specific options are defined the same way as + global options, but in the member zone subdomain: +
++masters.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN A 192.0.2.2 +label.masters.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN AAAA 2001:db8::2 +label.masters.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN TXT "tsig_key" +allow-query.5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN APL 1:10.0.0.0/24 ++
+ As would be expected, options defined for a specific zone override
+ the global options defined in the catalog zone. These in turn override
+ the global options defined in the catalog-zones
+ statement in the configuration file.
+
+ (Note that none of the global records an option will be inherited if
+ any records are defined for that option for the specific zone. For
+ example, if the zone had a masters record of type
+ A but not AAAA, then it would not inherit the
+ type AAAA record from the global option.)
+
+ BIND 9 fully supports all currently + defined forms of IPv6 name to address and address to name + lookups. It will also use IPv6 addresses to make queries when + running on an IPv6 capable system. +
+ ++ For forward lookups, BIND 9 supports + only AAAA records. RFC 3363 deprecated the use of A6 records, + and client-side support for A6 records was accordingly removed + from BIND 9. + However, authoritative BIND 9 name servers still + load zone files containing A6 records correctly, answer queries + for A6 records, and accept zone transfer for a zone containing A6 + records. +
+ ++ For IPv6 reverse lookups, BIND 9 supports + the traditional "nibble" format used in the + ip6.arpa domain, as well as the older, deprecated + ip6.int domain. + Older versions of BIND 9 + supported the "binary label" (also known as "bitstring") format, + but support of binary labels has been completely removed per + RFC 3363. + Many applications in BIND 9 do not understand + the binary label format at all any more, and will return an + error if given. + In particular, an authoritative BIND 9 + name server will not load a zone file containing binary labels. +
+ ++ For an overview of the format and structure of IPv6 addresses, + see the section called “IPv6 addresses (AAAA)”. +
+ ++ The IPv6 AAAA record is a parallel to the IPv4 A record, + and, unlike the deprecated A6 record, specifies the entire + IPv6 address in a single record. For example, +
+ ++$ORIGIN example.com. +host 3600 IN AAAA 2001:db8::1 ++ +
+ Use of IPv4-in-IPv6 mapped addresses is not recommended.
+ If a host has an IPv4 address, use an A record, not
+ a AAAA, with ::ffff:192.168.42.1 as
+ the address.
+
+ When looking up an address in nibble format, the address
+ components are simply reversed, just as in IPv4, and
+ ip6.arpa. is appended to the
+ resulting name.
+ For example, the following would provide reverse name lookup for
+ a host with address
+ 2001:db8::1.
+
+$ORIGIN 0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. +1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 14400 IN PTR ( + host.example.com. ) ++ +
BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch05.html b/doc/arm/Bv9ARM.ch05.html new file mode 100644 index 0000000000000000000000000000000000000000..66862bb1650b565dc1d3d3d8ce5f1ccbc7ad2c99 --- /dev/null +++ b/doc/arm/Bv9ARM.ch05.html @@ -0,0 +1,86 @@ + + + + + +Table of Contents
+ ++ Traditionally applications have been linked with a stub resolver + library that sends recursive DNS queries to a local caching name + server. +
++ IPv6 once introduced new complexity into the resolution process, + such as following A6 chains and DNAME records, and simultaneous + lookup of IPv4 and IPv6 addresses. Though most of the complexity was + then removed, these are hard or impossible + to implement in a traditional stub resolver. +
++ BIND 9 therefore can also provide resolution + services to local clients + using a combination of a lightweight resolver library and a resolver + daemon process running on the local host. These communicate using + a simple UDP-based protocol, the "lightweight resolver protocol" + that is distinct from and simpler than the full DNS protocol. +
+BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch06.html b/doc/arm/Bv9ARM.ch06.html new file mode 100644 index 0000000000000000000000000000000000000000..5927e6cd486dcdb929084d4f577bb0a125edb13a --- /dev/null +++ b/doc/arm/Bv9ARM.ch06.html @@ -0,0 +1,14638 @@ + + + + + +Table of Contents
++ BIND 9 configuration is broadly similar + to BIND 8; however, there are a few new + areas + of configuration, such as views. BIND + 8 configuration files should work with few alterations in BIND + 9, although more complex configurations should be reviewed to check + if they can be more efficiently implemented using the new features + found in BIND 9. +
+ +
+ BIND 4 configuration files can be
+ converted to the new format
+ using the shell script
+ contrib/named-bootconf/named-bootconf.sh.
+
+ Following is a list of elements used throughout the BIND configuration + file documentation: +
+|
+
+ |
+
+
+ The name of an |
+
|
+
+ |
+
+
+ A list of one or more
+ |
+
|
+
+ |
+
+
+ A named list of one or more |
+
|
+
+ |
+
+
+ A quoted string which will be used as
+ a DNS name, for example " |
+
|
+
+ |
+
+
+ A list of one or more |
+
|
+
+ |
+
+ + One to four integers valued 0 through + 255 separated by dots (`.'), such as 123, + 45.67 or 89.123.45.67. + + |
+
|
+
+ |
+
+
+ An IPv4 address with exactly four elements
+ in |
+
|
+
+ |
+
+ + An IPv6 address, such as 2001:db8::1234. + IPv6 scoped addresses that have ambiguity on their + scope zones must be disambiguated by an appropriate + zone ID with the percent character (`%') as + delimiter. It is strongly recommended to use + string zone names rather than numeric identifiers, + in order to be robust against system configuration + changes. However, since there is no standard + mapping for such names and identifier values, + currently only interface names as link identifiers + are supported, assuming one-to-one mapping between + interfaces and links. For example, a link-local + address fe80::1 on the link + attached to the interface ne0 + can be specified as fe80::1%ne0. + Note that on most systems link-local addresses + always have the ambiguity, and need to be + disambiguated. + + |
+
|
+
+ |
+
+
+ An |
+
|
+
+ |
+
+
+ A |
+
|
+
+ |
+
+
+ An IP port |
+
|
+
+ |
+
+
+ An IP network specified as an + When specifying a prefix involving a IPv6 scoped address + the scope may be omitted. In that case the prefix will + match packets from any scope. + + |
+
|
+
+ |
+
+
+ A |
+
|
+
+ |
+
+
+ A list of one or more
+ |
+
|
+
+ |
+
+ + A non-negative 32-bit integer + (i.e., a number between 0 and 4294967295, inclusive). + Its acceptable value might further + be limited by the context in which it is used. + + |
+
|
+
+ |
+
+
+ A quoted string which will be used as
+ a pathname, such as |
+
|
+
+ |
+
+
+ A list of an |
+
|
+
+ |
+
+
+ A 64-bit unsigned integer, or the keywords
+
+ Integers may take values
+ 0 <= value <= 18446744073709551615, though
+ certain parameters
+ (such as max-journal-size) may
+ use a more limited range within these extremes.
+ In most cases, setting a value to 0 does not
+ literally mean zero; it means "undefined" or
+ "as big as possible", depending on the context.
+ See the explanations of particular parameters
+ that use
+ Numeric values can optionally be followed by a
+ scaling factor:
+
+
+ |
+
|
+
+ |
+
+
+
+ The behavior is exactly the same as
+ |
+
|
+
+ |
+
+
+ Either |
+
|
+
+ |
+
+
+ One of |
+
+ +address_match_list=address_match_list_element; ... + +address_match_list_element= [ ! ] (ip_address|ip_prefix| + keykey_id|acl_name| {address_match_list} ) +
+ Address match lists are primarily used to determine access + control for various server operations. They are also used in + the listen-on and sortlist + statements. The elements which constitute an address match + list can be any of the following: +
++ Elements can be negated with a leading exclamation mark (`!'), + and the match list names "any", "none", "localhost", and + "localnets" are predefined. More information on those names + can be found in the description of the acl statement. +
+ ++ The addition of the key clause made the name of this syntactic + element something of a misnomer, since security keys can be used + to validate access without regard to a host or network address. + Nonetheless, the term "address match list" is still used + throughout the documentation. +
+ ++ When a given IP address or prefix is compared to an address + match list, the comparison takes place in approximately O(1) + time. However, key comparisons require that the list of keys + be traversed until a matching key is found, and therefore may + be somewhat slower. +
+ ++ The interpretation of a match depends on whether the list is being + used for access control, defining listen-on ports, or in a + sortlist, and whether the element was negated. +
+ ++ When used as an access control list, a non-negated match + allows access and a negated match denies access. If + there is no match, access is denied. The clauses + allow-notify, + allow-recursion, + allow-recursion-on, + allow-query, + allow-query-on, + allow-query-cache, + allow-query-cache-on, + allow-transfer, + allow-update, + allow-update-forwarding, + blackhole, and + keep-response-order all use address match + lists. Similarly, the listen-on option will cause the + server to refuse queries on any of the machine's + addresses which do not match the list. +
+ ++ Order of insertion is significant. If more than one element + in an ACL is found to match a given IP address or prefix, + preference will be given to the one that came + first in the ACL definition. + Because of this first-match behavior, an element that + defines a subset of another element in the list should + come before the broader element, regardless of whether + either is negated. For example, in + 1.2.3/24; ! 1.2.3.13; + the 1.2.3.13 element is completely useless because the + algorithm will match any lookup for 1.2.3.13 to the 1.2.3/24 + element. Using ! 1.2.3.13; 1.2.3/24 fixes + that problem by having 1.2.3.13 blocked by the negation, but + all other 1.2.3.* hosts fall through. +
++ The BIND 9 comment syntax allows for + comments to appear + anywhere that whitespace may appear in a BIND configuration + file. To appeal to programmers of all kinds, they can be written + in the C, C++, or shell/perl style. +
+ ++
+/* This is a BIND comment as in C */+
+
+// This is a BIND comment as in C+++
+
+# This is a BIND comment as in common UNIX shells +# and perl+
+
++ Comments may appear anywhere that whitespace may appear in + a BIND configuration file. +
++ C-style comments start with the two characters /* (slash, + star) and end with */ (star, slash). Because they are completely + delimited with these characters, they can be used to comment only + a portion of a line or to span multiple lines. +
++ C-style comments cannot be nested. For example, the following + is not valid because the entire comment ends with the first */: +
++ +
+/* This is the start of a comment. + This is still part of the comment. +/* This is an incorrect attempt at nesting a comment. */ + This is no longer in any comment. */ ++
+ +
+ ++ C++-style comments start with the two characters // (slash, + slash) and continue to the end of the physical line. They cannot + be continued across multiple physical lines; to have one logical + comment span multiple lines, each line must use the // pair. + For example: +
++ +
+// This is the start of a comment. The next line +// is a new comment, even though it is logically +// part of the previous comment. ++
+ +
+
+ Shell-style (or perl-style, if you prefer) comments start
+ with the character # (number sign)
+ and continue to the end of the
+ physical line, as in C++ comments.
+ For example:
+
+ +
+# This is the start of a comment. The next line +# is a new comment, even though it is logically +# part of the previous comment. ++
+ +
+ ++ You cannot use the semicolon (`;') character + to start a comment such as you would in a zone file. The + semicolon indicates the end of a configuration + statement. +
++ A BIND 9 configuration consists of + statements and comments. + Statements end with a semicolon. Statements and comments are the + only elements that can appear without enclosing braces. Many + statements contain a block of sub-statements, which are also + terminated with a semicolon. +
+ ++ The following statements are supported: +
+ +|
+ acl + |
+
+ + defines a named IP address + matching list, for access control and other uses. + + |
+
|
+ controls + |
+
+ + declares control channels to be used + by the rndc utility. + + |
+
|
+ include + |
+
+ + includes a file. + + |
+
|
+ key + |
+
+ + specifies key information for use in + authentication and authorization using TSIG. + + |
+
|
+ logging + |
+
+ + specifies what the server logs, and where + the log messages are sent. + + |
+
|
+ masters + |
+
+ + defines a named masters list for + inclusion in stub and slave zones' + masters or + also-notify lists. + + |
+
|
+ options + |
+
+ + controls global server configuration + options and sets defaults for other statements. + + |
+
|
+ server + |
+
+ + sets certain configuration options on + a per-server basis. + + |
+
|
+ statistics-channels + |
+
+ + declares communication channels to get access to + named statistics. + + |
+
|
+ trusted-keys + |
+
+ + defines trusted DNSSEC keys. + + |
+
|
+ managed-keys + |
+
+ + lists DNSSEC keys to be kept up to date + using RFC 5011 trust anchor maintenance. + + |
+
|
+ view + |
+
+ + defines a view. + + |
+
|
+ zone + |
+
+ + defines a zone. + + |
+
+ The logging and + options statements may only occur once + per + configuration. +
+ + ++ The acl statement assigns a symbolic + name to an address match list. It gets its name from a primary + use of address match lists: Access Control Lists (ACLs). +
+ ++ The following ACLs are built-in: +
+ +|
+ any + |
+
+ + Matches all hosts. + + |
+
|
+ none + |
+
+ + Matches no hosts. + + |
+
|
+ localhost + |
+
+ + Matches the IPv4 and IPv6 addresses of all network + interfaces on the system. When addresses are + added or removed, the localhost + ACL element is updated to reflect the changes. + + |
+
|
+ localnets + |
+
+ + Matches any host on an IPv4 or IPv6 network + for which the system has an interface. + When addresses are added or removed, + the localnets + ACL element is updated to reflect the changes. + Some systems do not provide a way to determine the prefix + lengths of + local IPv6 addresses. + In such a case, localnets + only matches the local + IPv6 addresses, just like localhost. + + |
+
controls { + [ inet (+ +ip_addr| * ) [ portip_port] allow {address_match_list} + [ keys {key_list} ] + [ read-onlyyes_or_no] ; ] + [ unixpathpermnumberownernumbergroupnumber+ [ keys {key_list} ] + [ read-onlyyes_or_no] ; ] + [ ...; ] +}; +
+ The controls statement declares control + channels to be used by system administrators to control the + operation of the name server. These control channels are + used by the rndc utility to send + commands to and retrieve non-DNS results from a name server. +
+ +
+ An inet control channel is a TCP socket
+ listening at the specified ip_port on the
+ specified ip_addr, which can be an IPv4 or IPv6
+ address. An ip_addr of * (asterisk) is
+ interpreted as the IPv4 wildcard address; connections will be
+ accepted on any of the system's IPv4 addresses.
+ To listen on the IPv6 wildcard address,
+ use an ip_addr of ::.
+ If you will only use rndc on the local host,
+ using the loopback address (127.0.0.1
+ or ::1) is recommended for maximum security.
+
+ If no port is specified, port 953 is used. The asterisk
+ "*" cannot be used for ip_port.
+
+ The ability to issue commands over the control channel is + restricted by the allow and + keys clauses. + Connections to the control channel are permitted based on the + address_match_list. This is for simple + IP address based filtering only; any key_id + elements of the address_match_list + are ignored. +
+ ++ A unix control channel is a UNIX domain + socket listening at the specified path in the file system. + Access to the socket is specified by the perm, + owner and group clauses. + Note on some platforms (SunOS and Solaris) the permissions + (perm) are applied to the parent directory + as the permissions on the socket itself are ignored. +
+ ++ The primary authorization mechanism of the command + channel is the key_list, which + contains a list of key_ids. + Each key_id in the key_list + is authorized to execute commands over the control channel. + See Remote Name Daemon Control application in the section called “Administrative Tools”) + for information about configuring keys in rndc. +
+ ++ If the read-only clause is enabled, the + control channel is limited to the following set of read-only + commands: nta -dump, + null, status, + showzone, testgen, and + zonestatus. By default, + read-only is not enabled and the control + channel allows read-write access. +
+ +
+ If no controls statement is present,
+ named will set up a default
+ control channel listening on the loopback address 127.0.0.1
+ and its IPv6 counterpart ::1.
+ In this case, and also when the controls statement
+ is present but does not have a keys clause,
+ named will attempt to load the command channel key
+ from the file rndc.key in
+ /etc (or whatever sysconfdir
+ was specified as when BIND was built).
+ To create a rndc.key file, run
+ rndc-confgen -a.
+
+ The rndc.key feature was created to
+ ease the transition of systems from BIND 8,
+ which did not have digital signatures on its command channel
+ messages and thus did not have a keys clause.
+
+ It makes it possible to use an existing BIND 8
+ configuration file in BIND 9 unchanged,
+ and still have rndc work the same way
+ ndc worked in BIND 8, simply by executing the
+ command rndc-confgen -a after BIND 9 is
+ installed.
+
+ Since the rndc.key feature
+ is only intended to allow the backward-compatible usage of
+ BIND 8 configuration files, this
+ feature does not
+ have a high degree of configurability. You cannot easily change
+ the key name or the size of the secret, so you should make a
+ rndc.conf with your own key if you
+ wish to change
+ those things. The rndc.key file
+ also has its
+ permissions set such that only the owner of the file (the user that
+ named is running as) can access it.
+ If you
+ desire greater flexibility in allowing other users to access
+ rndc commands, then you need to create
+ a
+ rndc.conf file and make it group
+ readable by a group
+ that contains the users who should have access.
+
+ To disable the command channel, use an empty + controls statement: + controls { };. +
+ ++ The include statement inserts the + specified file at the point where the include + statement is encountered. The include + statement facilitates the administration of configuration + files + by permitting the reading or writing of some things but not + others. For example, the statement could include private keys + that are readable only by the name server. +
+ +key+ +key_id{ + algorithmalgorithm_id; + secretsecret_string; +}; +
+ The key statement defines a shared + secret key for use with TSIG (see the section called “TSIG”) + or the command channel + (see the section called “controls Statement Definition and + Usage”). +
+ ++ The key statement can occur at the + top level + of the configuration file or inside a view + statement. Keys defined in top-level key + statements can be used in all views. Keys intended for use in + a controls statement + (see the section called “controls Statement Definition and + Usage”) + must be defined at the top level. +
+ +
+ The key_id, also known as the
+ key name, is a domain name uniquely identifying the key. It can
+ be used in a server
+ statement to cause requests sent to that
+ server to be signed with this key, or in address match lists to
+ verify that incoming requests have been signed with a key
+ matching this name, algorithm, and secret.
+
+ The algorithm_id is a string
+ that specifies a security/authentication algorithm. The
+ named server supports hmac-md5,
+ hmac-sha1, hmac-sha224,
+ hmac-sha256, hmac-sha384
+ and hmac-sha512 TSIG authentication.
+ Truncated hashes are supported by appending the minimum
+ number of required bits preceded by a dash, e.g.
+ hmac-sha1-80. The
+ secret_string is the secret
+ to be used by the algorithm, and is treated as a base-64
+ encoded string.
+
logging { + [ channel+ +channel_name{ + ( ( filepath_name+ [ versions (number|unlimited) ] + [ sizesize_spec] + [ suffix (increment|timestamp) ) + | syslogsyslog_facility+ | stderr + | null ) ; + [ severity (critical|error|warning|notice| +info|debug[level] |dynamic) ; ] + [ print-categoryyes_or_no; ] + [ print-severityyes_or_no; ] + [ print-time (yes|no|local|iso8601|iso8601-utc) ; + [ bufferedyes_or_no; ] + }; ] + [ categorycategory_name{ +channel_name; ... + }; ] + ... +}; +
+ The logging statement configures a + wide + variety of logging options for the name server. Its channel phrase + associates output methods, format options and severity levels with + a name that can then be used with the category phrase + to select how various classes of messages are logged. +
++ Only one logging statement is used to + define + as many channels and categories as are wanted. If there is no logging statement, + the logging configuration will be: +
+ +logging {
+ category default { default_syslog; default_debug; };
+ category unmatched { null; };
+};
+
+
+
+ If named is started with the
+ -L option, it logs to the specified file
+ at startup, instead of using syslog. In this case the logging
+ configuration will be:
+
logging {
+ category default { default_logfile; default_debug; };
+ category unmatched { null; };
+};
+
+
+
+ In BIND 9, the logging configuration
+ is only established when
+ the entire configuration file has been parsed. In BIND 8, it was
+ established as soon as the logging
+ statement
+ was parsed. When the server is starting up, all logging messages
+ regarding syntax errors in the configuration file go to the default
+ channels, or to standard error if the -g option
+ was specified.
+
+ All log output goes to one or more channels; + you can make as many of them as you want. +
+ ++ Every channel definition must include a destination clause that + says whether messages selected for the channel go to a file, to a + particular syslog facility, to the standard error stream, or are + discarded. It can optionally also limit the message severity level + that will be accepted by the channel (the default is + info), and whether to include a + named-generated time stamp, the + category name + and/or severity level (the default is not to include any). +
+ ++ The null destination clause + causes all messages sent to the channel to be discarded; + in that case, other options for the channel are meaningless. +
+ ++ The file destination clause directs + the channel to a disk file. It can include additional + arguments to specify how large the file is allowed to + become before it is rolled to a backup file + (size), how many backup versions of + the file will be saved each time this happens + (versions), and the format to use + for naming backup versions (suffix). +
+ ++ The size option is used to limit + log file growth. If the file ever exceeds the specified + size, then named will stop writing to the + file unless it has a versions option + associated with it. If backup versions are kept, the files + are rolled as described below. If there is no + versions option, no more data will + be written to the log until some out-of-band mechanism + removes or truncates the log to less than the maximum size. + The default behavior is not to limit the size of the file. +
+
+ File rolling only occurs when the file exceeds the size
+ specified with the size option. No
+ backup versions are kept by default; any existing
+ log file is simply appended. The
+ versions option specifies
+ how many backup versions of the file should be kept.
+ If set to unlimited, there is no limit.
+
+ The suffix option can be set to
+ either increment or
+ timestamp. If set to
+ timestamp, then when a log file is
+ rolled, it is saved with the current timestamp as a
+ file suffix. If set to increment,
+ then backup files are saved with incrementing numbers
+ as suffixes; older files are renamed when rolling.
+ For example, if versions
+ is set to 3 and suffix to
+ increment, then when
+ filename.log reaches the size
+ specified by size,
+ filename.log.1 is renamed to
+ filename.log.2,
+ filename.log.0 is renamed
+ to filename.log.1,
+ and filename.log is
+ renamed to filename.log.0,
+ whereupon a new filename.log is
+ opened.
+
+ Example usage of the size, + versions, and suffix + options: +
+ +channel an_example_channel {
+ file "example.log" versions 3 size 20m suffix increment;
+ print-time yes;
+ print-category yes;
+};
+
+
+ + The syslog destination clause + directs the + channel to the system log. Its argument is a + syslog facility as described in the syslog man + page. Known facilities are kern, user, + mail, daemon, auth, + syslog, lpr, news, + uucp, cron, authpriv, + ftp, local0, local1, + local2, local3, local4, + local5, local6 and + local7, however not all facilities + are supported on + all operating systems. + How syslog will handle messages + sent to + this facility is described in the syslog.conf man + page. If you have a system which uses a very old version of syslog that + only uses two arguments to the openlog() function, + then this clause is silently ignored. +
++ On Windows machines syslog messages are directed to the EventViewer. +
++ The severity clause works like syslog's + "priorities", except that they can also be used if you are writing + straight to a file rather than using syslog. + Messages which are not at least of the severity level given will + not be selected for the channel; messages of higher severity + levels + will be accepted. +
++ If you are using syslog, then the syslog.conf priorities + will also determine what eventually passes through. For example, + defining a channel facility and severity as daemon and debug but + only logging daemon.warning via syslog.conf will + cause messages of severity info and + notice to + be dropped. If the situation were reversed, with named writing + messages of only warning or higher, + then syslogd would + print all messages it received from the channel. +
+ ++ The stderr destination clause + directs the + channel to the server's standard error stream. This is intended + for + use when the server is running as a foreground process, for + example + when debugging a configuration. +
+ +
+ The server can supply extensive debugging information when
+ it is in debugging mode. If the server's global debug level is
+ greater
+ than zero, then debugging mode will be active. The global debug
+ level is set either by starting the named server
+ with the -d flag followed by a positive integer,
+ or by running rndc trace.
+ The global debug level
+ can be set to zero, and debugging mode turned off, by running rndc
+notrace. All debugging messages in the server have a debug
+ level, and higher debug levels give more detailed output. Channels
+ that specify a specific debug severity, for example:
+
channel specific_debug_level {
+ file "foo";
+ severity debug 3;
+};
+
+
+ + will get debugging output of level 3 or less any time the + server is in debugging mode, regardless of the global debugging + level. Channels with dynamic + severity use the + server's global debug level to determine what messages to print. +
+
+ print-time can be set to
+ yes, no,
+ or a time format specifier, which may be one of
+ local, iso8601 or
+ iso8601-utc. If set to
+ no, then the date and time will
+ not be logged. If set to yes
+ or local, the date and time are logged
+ in a human readable format, using the local time zone.
+ If set to iso8601 the local time is
+ logged in ISO8601 format. If set to
+ iso8601-utc, then the date and time
+ are logged in ISO8601 format, with time zone set to
+ UTC. The default is local.
+
+ print-time may + be specified for a syslog channel, + but it is usually + pointless since syslog also logs + the date and time. +
++ If print-category is + requested, then the + category of the message will be logged as well. Finally, if print-severity is + on, then the severity level of the message will be logged. The print- options may + be used in any combination, and will always be printed in the + following + order: time, category, severity. Here is an example where all + three print- options + are on: +
+ +
+ 28-Feb-2000 15:05:32.863 general: notice: running
+
+ If buffered has been turned on the output + to files will not be flushed after each log entry. By default + all log messages are flushed. +
+ +
+ There are four predefined channels that are used for
+ named's default logging as follows.
+ If named is started with the
+ -L then a
+ fifth channel default_logfile is added.
+ How they are
+ used is described in the section called “The category Phrase”.
+
channel default_syslog {
+ // send to syslog's daemon facility
+ syslog daemon;
+ // only send priority info and higher
+ severity info;
+
+channel default_debug {
+ // write to named.run in the working directory
+ // Note: stderr is used instead of "named.run" if
+ // the server is started with the '-g' option.
+ file "named.run";
+ // log at the server's current debug level
+ severity dynamic;
+};
+
+channel default_stderr {
+ // writes to stderr
+ stderr;
+ // only send priority info and higher
+ severity info;
+};
+
+channel null {
+ // toss anything sent to this channel
+ null;
+};
+
+channel default_logfile {
+ // this channel is only present if named is
+ // started with the -L option, whose argument
+ // provides the file name
+ file "...";
+ // log at the server's current debug level
+ severity dynamic;
+};
+
+
+
+ The default_debug channel has the
+ special
+ property that it only produces output when the server's debug
+ level is
+ nonzero. It normally writes to a file called named.run
+ in the server's working directory.
+
+ For security reasons, when the -u
+ command line option is used, the named.run file
+ is created only after named has
+ changed to the
+ new UID, and any debug output generated while named is
+ starting up and still running as root is discarded. If you need
+ to capture this output, you must run the server with the -L
+ option to specify a default logfile, or the -g
+ option to log to standard error which you can redirect to a file.
+
+ Once a channel is defined, it cannot be redefined. Thus you + cannot alter the built-in channels directly, but you can modify + the default logging by pointing categories at channels you have + defined. +
++ There are many categories, so you can send the logs you want + to see wherever you want, without seeing logs you don't want. If + you don't specify a list of channels for a category, then log + messages + in that category will be sent to the default category + instead. If you don't specify a default category, the following + "default default" is used: +
+ +category default { default_syslog; default_debug; };
+
+
+
+ If you start named with the
+ -L option then the default category is:
+
category default { default_logfile; default_debug; };
+
+
+ + As an example, let's say you want to log security events to + a file, but you also want keep the default logging behavior. You'd + specify the following: +
+ +channel my_security_channel {
+ file "my_security_file";
+ severity info;
+};
+category security {
+ my_security_channel;
+ default_syslog;
+ default_debug;
+};
+
+ + To discard all messages in a category, specify the null channel: +
+ +category xfer-out { null; };
+category notify { null; };
+
+
+ + Following are the available categories and brief descriptions + of the types of log information they contain. More + categories may be added in future BIND releases. +
+|
+ client + |
+
+ + Processing of client requests. + + |
+
|
+ cname + |
+
+ + Logs nameservers that are skipped due to them being + a CNAME rather than A / AAAA records. + + |
+
|
+ config + |
+
+ + Configuration file parsing and processing. + + |
+
|
+ database + |
+
+ + Messages relating to the databases used + internally by the name server to store zone and cache + data. + + |
+
|
+ default + |
+
+ + The default category defines the logging + options for those categories where no specific + configuration has been + defined. + + |
+
|
+ delegation-only + |
+
+ + Delegation only. Logs queries that have been + forced to NXDOMAIN as the result of a + delegation-only zone or a + delegation-only in a + forward, hint or stub zone declaration. + + |
+
|
+ dispatch + |
+
+ + Dispatching of incoming packets to the + server modules where they are to be processed. + + |
+
|
+ dnssec + |
+
+ + DNSSEC and TSIG protocol processing. + + |
+
|
+ dnstap + |
+
+ + The "dnstap" DNS traffic capture system. + + |
+
|
+ edns-disabled + |
+
+ + Log queries that have been forced to use plain + DNS due to timeouts. This is often due to + the remote servers not being RFC 1034 compliant + (not always returning FORMERR or similar to + EDNS queries and other extensions to the DNS + when they are not understood). In other words, this is + targeted at servers that fail to respond to + DNS queries that they don't understand. + ++ Note: the log message can also be due to + packet loss. Before reporting servers for + non-RFC 1034 compliance they should be re-tested + to determine the nature of the non-compliance. + This testing should prevent or reduce the + number of false-positive reports. + ++ Note: eventually named will have to stop + treating such timeouts as due to RFC 1034 non + compliance and start treating it as plain + packet loss. Falsely classifying packet + loss as due to RFC 1034 non compliance impacts + on DNSSEC validation which requires EDNS for + the DNSSEC records to be returned. + + |
+
|
+ general + |
+
+ + The catch-all. Many things still aren't + classified into categories, and they all end up here. + + |
+
|
+ lame-servers + |
+
+ + Lame servers. These are misconfigurations + in remote servers, discovered by BIND 9 when trying to + query those servers during resolution. + + |
+
|
+ network + |
+
+ + Network operations. + + |
+
|
+ notify + |
+
+ + The NOTIFY protocol. + + |
+
|
+ queries + |
+
+ + Specify where queries should be logged to. + ++ At startup, specifying the category queries will also + enable query logging unless querylog option has been + specified. + + +
+ The query log entry first reports a client object
+ identifier in @0x<hexadecimal-number>
+ format. Next, it reports the client's IP
+ address and port number, and the query name,
+ class and type. Next, it reports whether the
+ Recursion Desired flag was set (+ if set, -
+ if not set), whether the query was signed (S),
+ whether EDNS was in use along with the EDNS version
+ number (E(#)), whether TCP was used (T), whether
+ DO (DNSSEC Ok) was set (D), whether CD (Checking
+ Disabled) was set (C), whether a valid DNS Server
+ COOKIE was received (V), and whether a DNS
+ COOKIE option without a valid Server COOKIE was
+ present (K). After this the destination
+ address the query was sent to is reported.
+ Finally, if any CLIENT-SUBNET option
+ was present in the client query, it is
+ included in square brackets in the format
+ [ECS
+
+ + (The first part of this log message, showing the + client address/port number and query name, is + repeated in all subsequent log messages related + to the same query.) + + |
+
|
+ query-errors + |
+
+ + Information about queries that resulted in some + failure. + + |
+
|
+ rate-limit + |
+
+ + The start, periodic, and final notices of the + rate limiting of a stream of responses are logged at + info severity in this category. + These messages include a hash value of the domain name + of the response and the name itself, + except when there is insufficient memory to record + the name for the final notice + The final notice is normally delayed until about one + minute after rate limit stops. + A lack of memory can hurry the final notice, + in which case it starts with an asterisk (*). + Various internal events are logged at debug 1 level + and higher. + ++ Rate limiting of individual requests + is logged in the query-errors category. + + |
+
|
+ resolver + |
+
+ + DNS resolution, such as the recursive + lookups performed on behalf of clients by a caching name + server. + + |
+
|
+ rpz + |
+
+ + Information about errors in response policy zone files, + rewritten responses, and at the highest + debug levels, mere rewriting + attempts. + + |
+
|
+ security + |
+
+ + Approval and denial of requests. + + |
+
|
+ spill + |
+
+ + Logs queries that have been terminated, either by dropping + or responding with SERVFAIL, as a result of a fetchlimit + quota being exceeded. + + |
+
|
+ unmatched + |
+
+ + Messages that named was unable to determine the + class of or for which there was no matching view. + A one line summary is also logged to the client category. + This category is best sent to a file or stderr, by + default it is sent to + the null channel. + + |
+
|
+ update + |
+
+ + Dynamic updates. + + |
+
|
+ update-security + |
+
+ + Approval and denial of update requests. + + |
+
|
+ xfer-in + |
+
+ + Zone transfers the server is receiving. + + |
+
|
+ xfer-out + |
+
+ + Zone transfers the server is sending. + + |
+
+ The query-errors category is + specifically intended for debugging purposes: To identify + why and how specific queries result in responses which + indicate an error. + Messages of this category are therefore only logged + with debug levels. +
+ ++ At the debug levels of 1 or higher, each response with the + rcode of SERVFAIL is logged as follows: +
+
+ client 127.0.0.1#61502: query failed (SERVFAIL) for www.example.com/IN/AAAA at query.c:3880
+
+ This means an error resulting in SERVFAIL was
+ detected at line 3880 of source file
+ query.c.
+ Log messages of this level will particularly
+ help identify the cause of SERVFAIL for an
+ authoritative server.
+
+ At the debug levels of 2 or higher, detailed context + information of recursive resolutions that resulted in + SERVFAIL is logged. + The log message will look like as follows: +
++ +
++fetch completed at resolver.c:2970 for www.example.com/A +in 30.000183: timed out/success [domain:example.com, +referral:2,restart:7,qrysent:8,timeout:5,lame:0,neterr:0, +badresp:1,adberr:0,findfail:0,valfail:0] ++
+
+
+ The first part before the colon shows that a recursive
+ resolution for AAAA records of www.example.com completed
+ in 30.000183 seconds and the final result that led to the
+ SERVFAIL was determined at line 2970 of source file
+ resolver.c.
+
+ The following part shows the detected final result and the + latest result of DNSSEC validation. + The latter is always success when no validation attempt + is made. + In this example, this query resulted in SERVFAIL probably + because all name servers are down or unreachable, leading + to a timeout in 30 seconds. + DNSSEC validation was probably not attempted. +
+
+ The last part enclosed in square brackets shows statistics
+ information collected for this particular resolution
+ attempt.
+ The domain field shows the deepest zone
+ that the resolver reached;
+ it is the zone where the error was finally detected.
+ The meaning of the other fields is summarized in the
+ following table.
+
|
+
|
+
+ + The number of referrals the resolver received + throughout the resolution process. + In the above example this is 2, which are most + likely com and example.com. + + |
+
|
+
|
+
+
+ The number of cycles that the resolver tried
+ remote servers at the |
+
|
+
|
+
+
+ The number of queries the resolver sent at the
+ |
+
|
+
|
+
+ + The number of timeouts since the resolver + received the last response. + + |
+
|
+
|
+
+
+ The number of lame servers the resolver detected
+ at the |
+
|
+
|
+
+
+ The number of erroneous results that the
+ resolver encountered in sending queries
+ at the |
+
|
+
|
+
+
+ The number of unexpected responses (other than
+ |
+
|
+
|
+
+
+ Failures in finding remote server addresses
+ of the |
+
|
+
|
+
+ + Failures of resolving remote server addresses. + This is a total number of failures throughout + the resolution process. + + |
+
|
+
|
+
+
+ Failures of DNSSEC validation.
+ Validation failures are counted throughout
+ the resolution process (not limited to
+ the |
+
+ At the debug levels of 3 or higher, the same messages + as those at the debug 1 level are logged for other errors + than SERVFAIL. + Note that negative responses such as NXDOMAIN are not + regarded as errors here. +
++ At the debug levels of 4 or higher, the same messages + as those at the debug 2 level are logged for other errors + than SERVFAIL. + Unlike the above case of level 3, messages are logged for + negative responses. + This is because any unexpected results can be difficult to + debug in the recursion case. +
++masters+ +name[ portip_port] [ dscpip_dscp] { + (masters_list; ) | + (ip_addr[ portip_port] [ keykey] ; ) + ... +}; +
masters + lists allow for a common set of masters to be easily used by + multiple stub and slave zones in their masters + or also-notify lists. +
+
+ This is the grammar of the options
+ statement in the named.conf file:
+
options { + [ attach-cache+ +cache_name; ] + [ versionversion_string; ] + [ hostnamehostname_string; ] + [ server-idserver_id_string; ] + [ directorypath_name; ] + [ dnstap {message_type; ... } ; ] + [ dnstap-output (file|unix)path_name[ sizesize_spec] [ versions (number|unlimited) ] ; ] + [ dnstap-identity (string|hostname|none) ; ] + [ dnstap-version (string|none) ; ] + [ fstrm-set-buffer-hintnumber; ] + [ fstrm-set-flush-timeoutnumber; ] + [ fstrm-set-input-queue-sizenumber; ] + [ fstrm-set-output-notify-thresholdnumber; ] + [ fstrm-set-output-queue-model (mpsc|spsc) ; ] + [ fstrm-set-output-queue-sizenumber; ] + [ fstrm-set-reopen-intervalnumber; ] + [ geoip-directorypath_name; ] + [ key-directorypath_name; ] + [ managed-keys-directorypath_name; ] + [ new-zones-directorypath_name; ] + [ named-xferpath_name; ] + [ tkey-gssapi-keytabpath_name; ] + [ tkey-gssapi-credentialprincipal; ] + [ tkey-domaindomain_name; ] + [ tkey-dhkeykey_namekey_tag; ] + [ cache-filepath_name; ] + [ dump-filepath_name; ] + [ bindkeys-filepath_name; ] + [ lock-filepath_name; ] + [ secroots-filepath_name; ] + [ session-keyfilepath_name; ] + [ session-keynamekey_name; ] + [ session-keyalgalgorithm_id; ] + [ memstatisticsyes_or_no; ] + [ memstatistics-filepath_name; ] + [ pid-filepath_name; ] + [ recursing-filepath_name; ] + [ statistics-filepath_name; ] + [ zone-statistics (full|terse|none) ; ] + [ auth-nxdomainyes_or_no; ] + [ nxdomain-redirectstring; ] + [ deallocate-on-exityes_or_no; ] + [ dialupdialup_option; ] + [ fake-iqueryyes_or_no; ] + [ fetch-glueyes_or_no; ] + [ flush-zones-on-shutdownyes_or_no; ] + [ has-old-clientsyes_or_no; ] + [ host-statisticsyes_or_no; ] + [ host-statistics-maxnumber; ] + [ glue-cacheyes_or_no; ] + [ minimal-anyyes_or_no; ] + [ minimal-responses (yes_or_no|no-auth|no-auth-recursive) ; ] + [ multiple-cnamesyes_or_no; ] + [ notify (yes_or_no|explicit|master-only) ; ] + [ recursionyes_or_no; ] + [ send-cookieyes_or_no; ] + [ require-server-cookieyes_or_no; ] + [ cookie-algorithmalgorithm_id; ] + [ cookie-secretsecret_string; ] + [ nocookie-udp-sizenumber; ] + [ request-nsidyes_or_no; ] + [ rfc2308-type1yes_or_no; ] + [ use-id-poolyes_or_no; ] + [ maintain-ixfr-baseyes_or_no; ] + [ ixfr-from-differences (yes_or_no|master|slave) ; ] + [ auto-dnssec (allow|maintain|off) ; ] + [ dnssec-enableyes_or_no; ] + [ dnssec-validation (yes_or_no|auto) ; ] + [ dnssec-lookaside (auto|no|domaintrust-anchordomain) ; ] + [ dnssec-must-be-securedomain yes_or_no; ] + [ dnssec-accept-expiredyes_or_no; ] + [ forward (only|first) ; ] + [ forwarders { + (ip_addr[ portip_port] [ dscpip_dscp] ; ) + ... + } ; ] + [ dual-stack-servers [ portip_port] [ dscpip_dscp] { + ( (domain_name|ip_addr) [ portip_port] [ dscpip_dscp] ; ) + ... + } ; ] + [ check-names (master|slave|response) + (warn|fail|ignore) ; ] + [ check-dup-records (warn|fail|ignore) ; ] + [ check-mx (warn|fail|ignore) ; ] + [ check-wildcardyes_or_no; ] + [ check-integrityyes_or_no; ] + [ check-mx-cname (warn|fail|ignore) ; ] + [ check-srv-cname (warn|fail|ignore) ; ] + [ check-siblingyes_or_no; ] + [ check-spf (warn|ignore) ; ] + [ allow-new-zonesyes_or_no; ] + [ allow-notify {address_match_list} ; ] + [ allow-query {address_match_list} ; ] + [ allow-query-on {address_match_list} ; ] + [ allow-query-cache {address_match_list} ; ] + [ allow-query-cache-on {address_match_list} ; ] + [ allow-transfer {address_match_list} ; ] + [ allow-recursion {address_match_list} ; ] + [ allow-recursion-on {address_match_list} ; ] + [ allow-update {address_match_list} ] + [ allow-update-forwarding {address_match_list} ; ] + [ automatic-interface-scanyes_or_no; ] + [ geoip-use-ecsyes_or_no; ] + [ update-check-kskyes_or_no; ] + [ dnssec-update-mode (maintain|no-resign) ; ] + [ dnssec-dnskey-kskonlyyes_or_no; ] + [ dnssec-loadkeys-intervalnumber; ] + [ dnssec-secure-to-insecureyes_or_no; ] + [ try-tcp-refreshyes_or_no; ] + [ allow-v6-synthesis {address_match_list} ; ] + [ blackhole {address_match_list} ; ] + [ keep-response-order {address_match_list} ; ] + [ no-case-compress {address_match_list} ; ] + [ message-compressionyes_or_no; ] + [ use-v4-udp-ports {port_list} ; ] + [ avoid-v4-udp-ports {port_list} ; ] + [ use-v6-udp-ports {port_list} ; ] + [ avoid-v6-udp-ports {port_list} ; ] + [ listen-on [ portip_port] [ dscpip_dscp] {address_match_list} ; ] + [ listen-on-v6 [ portip_port] [ dscpip_dscp] {address_match_list} ; ] + [ query-source ( [ address ] (ip4_addr|*) ) + [ port (ip_port|*) ] [ dscpip_dscp] ] ; + [ query-source-v6 ( [ address ] (ip6_addr|*) ) + [ port (ip_port|*) ] [ dscpip_dscp] ] ; + [ use-queryport-poolyes_or_no; ] + [ queryport-pool-portsnumber; ] + [ queryport-pool-updateintervalnumber; ] + [ max-recordsnumber; ] + [ max-transfer-time-innumber; ] + [ max-transfer-time-outnumber; ] + [ max-transfer-idle-innumber; ] + [ max-transfer-idle-outnumber; ] + [ reserved-socketsnumber; ] + [ recursive-clientsnumber; ] + [ tcp-clientsnumber; ] + [ clients-per-querynumber; ] + [ max-clients-per-querynumber; ] + [ fetches-per-servernumber[ (drop|fail) ] ; ] + [ fetches-per-zonenumber[ (drop|fail) ] ; ] + [ fetch-quota-paramsnumber fixedpoint fixedpoint fixedpoint; ] + [ notify-ratenumber; ] + [ startup-notify-ratenumber; ] + [ serial-query-ratenumber; ] + [ serial-queriesnumber; ] + [ tcp-listen-queuenumber; ] + [ tcp-initial-timeoutnumber; ] + [ tcp-idle-timeoutnumber; ] + [ tcp-keepalive-timeoutnumber; ] + [ tcp-advertised-timeoutnumber; ] + [ transfer-format (one-answer|many-answers) ; ] + [ transfer-message-sizenumber; ] + [ transfers-innumber; ] + [ transfers-outnumber; ] + [ transfers-per-nsnumber; ] + [ transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ alt-transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ alt-transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ use-alt-transfer-sourceyes_or_no; ] + [ notify-delayseconds; ] + [ notify-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ notify-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ notify-to-soayes_or_no; ] + [ also-notify [ portip_port] [ dscpip_dscp] { + (masters|ip_addr[ portip_port] ) [ keykey_name] ; + ... + } ; ] + [ max-ixfr-log-sizenumber; ] + [ max-journal-sizesize_spec; ] + [ coresizesize_spec; ] + [ datasizesize_spec; ] + [ filessize_spec; ] + [ stacksizesize_spec; ] + [ cleaning-intervalnumber; ] + [ heartbeat-intervalnumber; ] + [ interface-intervalnumber; ] + [ statistics-intervalnumber; ] + [ topology {address_match_list} ; ] + [ sortlist {address_match_list} ; ] + [ rrset-order {order_spec; ... } ; ] + [ lame-ttlnumber; ] + [ max-ncache-ttlnumber; ] + [ max-cache-ttlnumber; ] + [ max-stale-ttlnumber; ] + [ max-zone-ttl (unlimited|number) ; ] + [ stale-answer-enableyes_or_no; ] + [ stale-answer-ttlnumber; ] + [ serial-update-method (increment|unixtime|date) ; ] + [ servfail-ttlnumber; ] + [ sig-validity-intervalnumber[number] ; ] + [ sig-signing-nodesnumber; ] + [ sig-signing-signaturesnumber; ] + [ sig-signing-typenumber; ] + [ min-rootsnumber; ] + [ use-ixfryes_or_no; ] + [ provide-ixfryes_or_no; ] + [ request-ixfryes_or_no; ] + [ request-expireyes_or_no; ] + [ treat-cr-as-spaceyes_or_no; ] + [ min-refresh-timenumber; ] + [ max-refresh-timenumber; ] + [ min-retry-timenumber; ] + [ max-retry-timenumber; ] + [ nta-lifetimeduration; ] + [ nta-recheckduration; ] + [ portip_port; ] + [ dscpip_dscp; ] + [ random-devicepath_name; ] + [ max-cache-sizesize_or_percent; ] + [ match-mapped-addressesyes_or_no; ] + [ filter-aaaa-on-v4 (yes_or_no|break-dnssec) ; ] + [ filter-aaaa-on-v6 (yes_or_no|break-dnssec) ; ] + [ filter-aaaa {address_match_list} ; ] + [ dns64ipv6-prefix{ + [ clients {address_match_list} ; ] + [ mapped {address_match_list} ; ] + [ exclude {address_match_list} ; ] + [ suffixip6-address; ] + [ recursive-onlyyes_or_no; ] + [ break-dnssecyes_or_no; ] + } ; ] + [ dns64-servername] + [ dns64-contactname] + [ preferred-glue (A|AAAA|none); ] + [ edns-udp-sizenumber; ] + [ max-udp-sizenumber; ] + [ response-padding {address_match_list} block-sizenumber; ] + [ max-rsa-exponent-sizenumber; ] + [ root-delegation-only [ exclude {namelist} ] ; ] + [ querylogyes_or_no; ] + [ disable-algorithmsdomain{algorithm; ... } ; ] + [ disable-ds-digestsdomain{digest_type; ... } ; ] + [ max-recursion-depthnumber; ] + [ max-recursion-queriesnumber; ] + [ masterfile-format (text|raw|map) ; ] + [ masterfile-style (relative|full) ; ] + [ empty-servername; ] + [ empty-contactname; ] + [ empty-zones-enableyes_or_no; ] + [ disable-empty-zonezone_name; ] + [ zero-no-soa-ttlyes_or_no; ] + [ zero-no-soa-ttl-cacheyes_or_no; ] + [ resolver-query-timeoutnumber; ] + [ deny-answer-addresses {address_match_list} + [ except-from {namelist} ] ; ] + [ deny-answer-aliases {namelist} + [ except-from {namelist} ] ; ] + [ prefetchnumber[number] ; ] + [ rate-limit { + [ responses-per-secondnumber; ] + [ referrals-per-secondnumber; ] + [ nodata-per-secondnumber; ] + [ nxdomains-per-secondnumber; ] + [ errors-per-secondnumber; ] + [ all-per-secondnumber; ] + [ windownumber; ] + [ log-onlyyes_or_no; ] + [ qps-scalenumber; ] + [ ipv4-prefix-lengthnumber; ] + [ ipv6-prefix-lengthnumber; ] + [ slipnumber; ] + [ exempt-clients {address_match_list} ; ] + [ max-table-sizenumber; ] + [ min-table-sizenumber; ] + } ; ] + [ response-policy { + zonezone_name+ [ policy ( given | disabled | passthru | drop | + tcp-only | nxdomain | nodata | cnamedomain) ] + [ recursive-onlyyes_or_no] + [ logyes_or_no] + [ max-policy-ttlnumber] + [ min-update-intervalnumber] + [ nsip-enableyes_or_no] + [ nsdname-enableyes_or_no] ; + ... + } [ recursive-onlyyes_or_no] + [ max-policy-ttlnumber] + [ min-update-intervalnumber] + [ break-dnssecyes_or_no] + [ min-ns-dotsnumber] + [ nsip-wait-recurseyes_or_no] + [ qname-wait-recurseyes_or_no] + [ nsip-enableyes_or_no] + [ nsdname-enableyes_or_no] + [ dnsrps-enableyes_or_no] + [ dnsrps-options {parameters} ] ; ] + [ catalog-zones { + zonequoted_string+ [default-masters[ portip_port] [ dscpip_dscp] { + (masters_list|ip_addr[portip_port] [ keykey_name] ) ; + ... + } ] + [ zone-directorypath_name] + [ in-memoryyes_or_no] + [ min-update-intervalinterval] ; + ... + } ; ] + [ v6-biasnumber; ] +} ; ] +
+ The options statement sets up global + options + to be used by BIND. This statement + may appear only + once in a configuration file. If there is no options + statement, an options block with each option set to its default will + be used. +
+ ++ Allows multiple views to share a single cache + database. + Each view has its own cache database by default, but + if multiple views have the same operational policy + for name resolution and caching, those views can + share a single cache to save memory and possibly + improve resolution efficiency by using this option. +
+ ++ The attach-cache option + may also be specified in view + statements, in which case it overrides the + global attach-cache option. +
+ +
+ The cache_name specifies
+ the cache to be shared.
+ When the named server configures
+ views which are supposed to share a cache, it
+ creates a cache with the specified name for the
+ first view of these sharing views.
+ The rest of the views will simply refer to the
+ already created cache.
+
+ One common configuration to share a cache would be to + allow all views to share a single cache. + This can be done by specifying + the attach-cache as a global + option with an arbitrary name. +
+ ++ Another possible operation is to allow a subset of + all views to share a cache while the others to + retain their own caches. + For example, if there are three views A, B, and C, + and only A and B should share a cache, specify the + attach-cache option as a view A (or + B)'s option, referring to the other view name: +
+ +
+ view "A" {
+ // this view has its own cache
+ ...
+ };
+ view "B" {
+ // this view refers to A's cache
+ attach-cache "A";
+ };
+ view "C" {
+ // this view has its own cache
+ ...
+ };
+
+
+ + Views that share a cache must have the same policy + on configurable parameters that may affect caching. + The current implementation requires the following + configurable options be consistent among these + views: + check-names, + cleaning-interval, + dnssec-accept-expired, + dnssec-validation, + max-cache-ttl, + max-ncache-ttl, + max-stale-ttl, + max-cache-size, and + zero-no-soa-ttl. +
+ ++ Note that there may be other parameters that may + cause confusion if they are inconsistent for + different views that share a single cache. + For example, if these views define different sets of + forwarders that can return different answers for the + same question, sharing the answer does not make + sense or could even be harmful. + It is administrator's responsibility to ensure + configuration differences in different views do + not cause disruption with a shared cache. +
+
+ The working directory of the server.
+ Any non-absolute pathnames in the configuration file will be
+ taken
+ as relative to this directory. The default location for most
+ server
+ output files (e.g. named.run)
+ is this directory.
+ If a directory is not specified, the working directory
+ defaults to `.', the directory from
+ which the server
+ was started. The directory specified should be an absolute
+ path.
+
+ dnstap is a fast, flexible method + for capturing and logging DNS traffic. Developed by + Robert Edmonds at Farsight Security, Inc., and supported + by multiple DNS implementations, dnstap + uses + libfstrm (a lightweight high-speed + framing library, see + https://github.com/farsightsec/fstrm) to send + event payloads which are encoded using Protocol Buffers + (libprotobuf-c, a mechanism for + serializing structured data developed + by Google, Inc.; see + https://developers.google.com/protocol-buffers). +
+
+ To enable dnstap at compile time,
+ the fstrm and protobuf-c
+ libraries must be available, and BIND must be configured with
+ --enable-dnstap.
+
+ The dnstap option is a bracketed list
+ of message types to be logged. These may be set differently
+ for each view. Supported types are client,
+ auth, resolver, and
+ forwarder. Specifying type
+ all will cause all dnstap
+ messages to be logged, regardless of type.
+
+ Each type may take an additional argument to indicate whether
+ to log query messages or
+ response messages; if not specified,
+ both queries and responses are logged.
+
+ Example: To log all authoritative queries and responses, + recursive client responses, and upstream queries sent by + the resolver, use: +
+dnstap {
+ auth;
+ client response;
+ resolver query;
+};
+
++
++ Logged dnstap messages can be parsed + using the dnstap-read utility (see + dnstap-read(1) for details). +
++ For more information on dnstap, see + http://dnstap.info. +
+
+ The fstrm library has a number of tunables that are exposed
+ in named.conf, and can be modified
+ if necessary to improve performance or prevent loss of data.
+ These are:
+
mpsc
+ (multiple producer, single consumer); the other
+ option is spsc (single producer,
+ single consumer).
+
+ IOV_MAX,
+ and the default is 64.
+
+ + Note that all of the above minimum, maximum, and default + values are set by the libfstrm library, + and may be subject to change in future versions of the + library. See the libfstrm documentation + for more information. +
++ Configures the path to which the dnstap + frame stream will be sent if dnstap + is enabled at compile time and active. +
+
+ The first argument is either file or
+ unix, indicating whether the destination
+ is a file or a UNIX domain socket. The second argument
+ is the path of the file or socket. (Note: when using a
+ socket, dnstap messages will
+ only be sent if another process such as
+ fstrm_capture
+ (provided with libfstrm) is listening on
+ the socket.)
+
+ If the first argument is file, then
+ up to three additional options can be added:
+ size indicates the size to which a
+ dnstap log file can grow before being
+ rolled to a new file; versions
+ specifies the number of rolled log files to retain; and
+ suffix indicates whether to retain
+ rolled log files with an incrementing counter as the
+ suffix (increment) or with the
+ current timestamp (timestamp).
+ These are similar to the size,
+ versions, and suffix
+ options in a logging channel.
+ The default is to allow dnstap log
+ files to grow to any size without rolling.
+
+ dnstap-output can only be set globally + in options. Currently, it can only be + set once while named is running; + once set, it cannot be changed by + rndc reload or + rndc reconfig. +
+
+ Specifies an identity string to send in
+ dnstap messages. If set to
+ hostname, which is the default, the
+ server's hostname will be sent. If set to
+ none, no identity string will be sent.
+
+ Specifies a version string to send in
+ dnstap messages. The default is the
+ version number of the BIND release. If set to
+ none, no version string will be sent.
+
+ Specifies the directory containing GeoIP
+ .dat database files for GeoIP
+ initialization. By default, this option is unset
+ and the GeoIP support will use libGeoIP's
+ built-in directory.
+ (For details, see the section called “acl Statement Definition and
+ Usage” about the
+ geoip ACL.)
+
+ When performing dynamic update of secure zones, the
+ directory where the public and private DNSSEC key files
+ should be found, if different than the current working
+ directory. (Note that this option has no effect on the
+ paths for files containing non-DNSSEC keys such as
+ bind.keys,
+ rndc.key or
+ session.key.)
+
+ When named is built with liblmdb, + this option sets a maximum size for the memory map of + the new-zone database (NZD) in LMDB database format. + This database is used to store configuration information + for zones added using rndc addzone. + Note that this is not the NZD database file size, but + the largest size that the database may grow to. +
++ Because the database file is memory mapped, its size is + limited by the address space of the named process. The + default of 32 megabytes was chosen to be usable with + 32-bit named builds. The largest + permitted value is 1 terabyte. Given typical zone + configurations without elaborate ACLs, a 32 MB NZD file + ought to be able to hold configurations of about 100,000 + zones. +
++ Specifies the directory in which to store the files that + track managed DNSSEC keys. By default, this is the working + directory. +
+
+ If named is not configured to use views,
+ then managed keys for the server will be tracked in a single
+ file called managed-keys.bind.
+ Otherwise, managed keys will be tracked in separate files,
+ one file per view; each file name will be the view name
+ (or, if it contains characters that are incompatible with
+ use as a file name, the SHA256 hash of the view name),
+ followed by the extension
+ .mkeys.
+
+ (Note: in previous releases, file names for views + always used the SHA256 hash of the view name. To ensure + compatibility after upgrade, if a file using the old + name format is found to exist, it will be used instead + of the new format.) +
++ Specifies the directory in which to store the configuration + parameters for zones added via rndc addzone. + By default, this is the working directory. +
++ This option is obsolete. It + was used in BIND 8 to specify + the pathname to the named-xfer + program. In BIND 9, no separate + named-xfer program is needed; + its functionality is built into the name server. +
++ The KRB5 keytab file to use for GSS-TSIG updates. If + this option is set and tkey-gssapi-credential is not + set, then updates will be allowed with any key + matching a principal in the specified keytab. +
+
+ The security credential with which the server should
+ authenticate keys requested by the GSS-TSIG protocol.
+ Currently only Kerberos 5 authentication is available
+ and the credential is a Kerberos principal which the
+ server can acquire through the default system key
+ file, normally /etc/krb5.keytab.
+ The location keytab file can be overridden using the
+ tkey-gssapi-keytab option. Normally this principal is
+ of the form "DNS/server.domain".
+ To use GSS-TSIG, tkey-domain must
+ also be set if a specific keytab is not set with
+ tkey-gssapi-keytab.
+
+ The domain appended to the names of all shared keys
+ generated with TKEY. When a
+ client requests a TKEY exchange,
+ it may or may not specify the desired name for the
+ key. If present, the name of the shared key will
+ be client specified part +
+ tkey-domain. Otherwise, the
+ name of the shared key will be random hex
+ digits + tkey-domain.
+ In most cases, the domainname
+ should be the server's domain name, or an otherwise
+ non-existent subdomain like
+ "_tkey.domainname". If you are
+ using GSS-TSIG, this variable must be defined, unless
+ you specify a specific keytab using tkey-gssapi-keytab.
+
+ The Diffie-Hellman key used by the server
+ to generate shared keys with clients using the Diffie-Hellman
+ mode
+ of TKEY. The server must be
+ able to load the
+ public and private keys from files in the working directory.
+ In
+ most cases, the key_name should be the server's host name.
+
+ This is for testing only. Do not use. +
+
+ The pathname of the file the server dumps
+ the database to when instructed to do so with
+ rndc dumpdb.
+ If not specified, the default is named_dump.db.
+
+ The pathname of the file the server writes memory
+ usage statistics to on exit. If not specified,
+ the default is named.memstats.
+
+ The pathname of a file on which named will
+ attempt to acquire a file lock when starting up for
+ the first time; if unsuccessful, the server will
+ will terminate, under the assumption that another
+ server is already running. If not specified, the default is
+ /var/run/named/named.lock.
+
+ Specifying lock-file none disables the
+ use of a lock file. lock-file is
+ ignored if named was run using the -X
+ option, which overrides it. Changes to
+ lock-file are ignored if
+ named is being reloaded or
+ reconfigured; it is only effective when the server is
+ first started up.
+
+ The pathname of the file the server writes its process ID
+ in. If not specified, the default is
+ /var/run/named/named.pid.
+ The PID file is used by programs that want to send signals to
+ the running
+ name server. Specifying pid-file none disables the
+ use of a PID file — no file will be written and any
+ existing one will be removed. Note that none
+ is a keyword, not a filename, and therefore is not enclosed
+ in
+ double quotes.
+
+ The pathname of the file the server dumps
+ the queries that are currently recursing when instructed
+ to do so with rndc recursing.
+ If not specified, the default is named.recursing.
+
+ The pathname of the file the server appends statistics
+ to when instructed to do so using rndc stats.
+ If not specified, the default is named.stats in the
+ server's current directory. The format of the file is
+ described
+ in the section called “The Statistics File”.
+
+ The pathname of a file to override the built-in trusted
+ keys provided by named.
+ See the discussion of dnssec-lookaside
+ and dnssec-validation for details.
+ If not specified, the default is
+ /etc/bind.keys.
+
+ The pathname of the file the server dumps
+ security roots to when instructed to do so with
+ rndc secroots.
+ If not specified, the default is
+ named.secroots.
+
+ The pathname of the file into which to write a TSIG
+ session key generated by named for use by
+ nsupdate -l. If not specified, the
+ default is /var/run/named/session.key.
+ (See the section called “Dynamic Update Policies”, and in
+ particular the discussion of the
+ update-policy statement's
+ local option for more
+ information about this feature.)
+
+ The key name to use for the TSIG session key. + If not specified, the default is "local-ddns". +
++ The algorithm to use for the TSIG session key. + Valid values are hmac-sha1, hmac-sha224, hmac-sha256, + hmac-sha384, hmac-sha512 and hmac-md5. If not + specified, the default is hmac-sha256. +
++ The UDP/TCP port number the server uses for + receiving and sending DNS protocol traffic. + The default is 53. This option is mainly intended for server + testing; + a server using a port other than 53 will not be able to + communicate with + the global DNS. +
++ The global Differentiated Services Code Point (DSCP) + value to classify outgoing DNS traffic on operating + systems that support DSCP. Valid values are 0 through 63. + It is not configured by default. +
+
+ The source of entropy to be used by the server. Entropy is
+ primarily needed
+ for DNSSEC operations, such as TKEY transactions and dynamic
+ update of signed
+ zones. This options specifies the device (or file) from which
+ to read
+ entropy. If this is a file, operations requiring entropy will
+ fail when the
+ file has been exhausted. If not specified, the default value
+ is
+ /dev/random
+ (or equivalent) when present, and none otherwise. The
+ random-device option takes
+ effect during
+ the initial configuration load at server startup time and
+ is ignored on subsequent reloads.
+
+ If specified, the listed type (A or AAAA) will be emitted + before other glue + in the additional section of a query response. + The default is to prefer A records when responding + to queries that arrived via IPv4 and AAAA when + responding to queries that arrived via IPv6. +
++ Turn on enforcement of delegation-only in TLDs + (top level domains) and root zones with an optional + exclude list. +
++ DS queries are expected to be made to and be answered by + delegation only zones. Such queries and responses are + treated as an exception to delegation-only processing + and are not converted to NXDOMAIN responses provided + a CNAME is not discovered at the query name. +
++ If a delegation only zone server also serves a child + zone it is not always possible to determine whether + an answer comes from the delegation only zone or the + child zone. SOA NS and DNSKEY records are apex + only records and a matching response that contains + these records or DS is treated as coming from a + child zone. RRSIG records are also examined to see + if they are signed by a child zone or not. The + authority section is also examined to see if there + is evidence that the answer is from the child zone. + Answers that are determined to be from a child zone + are not converted to NXDOMAIN responses. Despite + all these checks there is still a possibility of + false negatives when a child zone is being served. +
++ Similarly false positives can arise from empty nodes + (no records at the name) in the delegation only zone + when the query type is not ANY. +
++ Note some TLDs are not delegation only (e.g. "DE", "LV", + "US" and "MUSEUM"). This list is not exhaustive. +
+ +
+options {
+ root-delegation-only exclude { "de"; "lv"; "us"; "museum"; };
+};
+
+
+ + Disable the specified DNSSEC algorithms at and below the + specified name. + Multiple disable-algorithms + statements are allowed. + Only the best match disable-algorithms + clause will be used to determine which algorithms are used. +
++ If all supported algorithms are disabled, the zones covered + by the disable-algorithms will be treated + as insecure. +
++ Disable the specified DS/DLV digest types at and below the + specified name. + Multiple disable-ds-digests + statements are allowed. + Only the best match disable-ds-digests + clause will be used to determine which digest types are used. +
++ If all supported digest types are disabled, the zones covered + by the disable-ds-digests will be treated + as insecure. +
++ When set, dnssec-lookaside provides the + validator with an alternate method to validate DNSKEY + records at the top of a zone. When a DNSKEY is at or + below a domain specified by the deepest + dnssec-lookaside, and the normal DNSSEC + validation has left the key untrusted, the trust-anchor + will be appended to the key name and a DLV record will be + looked up to see if it can validate the key. If the DLV + record validates a DNSKEY (similarly to the way a DS + record does) the DNSKEY RRset is deemed to be trusted. +
+
+ If dnssec-lookaside is set to
+ auto, then built-in default
+ values for the DLV domain and trust anchor will be
+ used, along with a built-in key for validation.
+
+ If dnssec-lookaside is set to
+ no, then dnssec-lookaside
+ is not used.
+
+ The default DLV key is stored in the file
+ bind.keys;
+ named will load that key at
+ startup if dnssec-lookaside is set to
+ auto. A copy of the file is
+ installed along with BIND 9, and is
+ current as of the release date. If the DLV key expires, a
+ new copy of bind.keys can be downloaded
+ from https://www.isc.org/solutions/dlv/.
+
+ (To prevent problems if bind.keys is
+ not found, the current key is also compiled in to
+ named. Relying on this is not
+ recommended, however, as it requires named
+ to be recompiled with a new key when the DLV key expires.)
+
+ NOTE: named only loads certain specific
+ keys from bind.keys: those for the
+ DLV zone and for the DNS root zone. The file cannot be
+ used to store keys for other zones.
+
+ Specify hierarchies which must be or may not be secure
+ (signed and validated). If yes,
+ then named will only accept answers if
+ they are secure. If no, then normal
+ DNSSEC validation applies allowing for insecure answers to
+ be accepted. The specified domain must be under a
+ trusted-keys or
+ managed-keys statement, or
+ dnssec-lookaside must be active.
+
+ This directive instructs named to + return mapped IPv4 addresses to AAAA queries when + there are no AAAA records. It is intended to be + used in conjunction with a NAT64. Each + dns64 defines one DNS64 prefix. + Multiple DNS64 prefixes can be defined. +
++ Compatible IPv6 prefixes have lengths of 32, 40, 48, 56, + 64 and 96 as per RFC 6052. +
++ Additionally a reverse IP6.ARPA zone will be created for + the prefix to provide a mapping from the IP6.ARPA names + to the corresponding IN-ADDR.ARPA names using synthesized + CNAMEs. dns64-server and + dns64-contact can be used to specify + the name of the server and contact for the zones. These + are settable at the view / options level. These are + not settable on a per-prefix basis. +
+
+ Each dns64 supports an optional
+ clients ACL that determines which
+ clients are affected by this directive. If not defined,
+ it defaults to any;.
+
+ Each dns64 supports an optional
+ mapped ACL that selects which
+ IPv4 addresses are to be mapped in the corresponding
+ A RRset. If not defined it defaults to
+ any;.
+
+ Normally, DNS64 won't apply to a domain name that + owns one or more AAAA records; these records will + simply be returned. The optional + exclude ACL allows specification + of a list of IPv6 addresses that will be ignored + if they appear in a domain name's AAAA records, and + DNS64 will be applied to any A records the domain + name owns. If not defined, exclude + defaults to ::ffff:0.0.0.0/96. +
+
+ A optional suffix can also
+ be defined to set the bits trailing the mapped
+ IPv4 address bits. By default these bits are
+ set to ::. The bits
+ matching the prefix and mapped IPv4 address
+ must be zero.
+
+ If recursive-only is set to + yes the DNS64 synthesis will + only happen for recursive queries. The default + is no. +
++ If break-dnssec is set to + yes the DNS64 synthesis will + happen even if the result, if validated, would + cause a DNSSEC validation failure. If this option + is set to no (the default), the DO + is set on the incoming query, and there are RRSIGs on + the applicable records, then synthesis will not happen. +
+
+ acl rfc1918 { 10/8; 192.168/16; 172.16/12; };
+
+ dns64 64:FF9B::/96 {
+ clients { any; };
+ mapped { !rfc1918; any; };
+ exclude { 64:FF9B::/96; ::ffff:0000:0000/96; };
+ suffix ::;
+ };
+
+
+ When a zone is configured with auto-dnssec
+ maintain; its key repository must be checked
+ periodically to see if any new keys have been added
+ or any existing keys' timing metadata has been updated
+ (see dnssec-keygen(8) and
+ dnssec-settime(8)). The
+ dnssec-loadkeys-interval option
+ sets the frequency of automatic repository checks, in
+ minutes. The default is 60 (1 hour),
+ the minimum is 1 (1 minute), and the
+ maximum is 1440 (24 hours); any higher
+ value is silently reduced.
+
+ If this option is set to its default value of
+ maintain in a zone of type
+ master which is DNSSEC-signed
+ and configured to allow dynamic updates (see
+ the section called “Dynamic Update Policies”), and
+ if named has access to the
+ private signing key(s) for the zone, then
+ named will automatically sign all new
+ or changed records and maintain signatures for the zone
+ by regenerating RRSIG records whenever they approach
+ their expiration date.
+
+ If the option is changed to no-resign,
+ then named will sign all new or
+ changed records, but scheduled maintenance of
+ signatures is disabled.
+
+ With either of these settings, named
+ will reject updates to a DNSSEC-signed zone when the
+ signing keys are inactive or unavailable to
+ named. (A planned third option,
+ external, will disable all automatic
+ signing and allow DNSSEC data to be submitted into a zone
+ via dynamic update; this is not yet implemented.)
+
+ Species the default lifetime, in seconds, + that will be used for negative trust anchors added + via rndc nta. +
++ A negative trust anchor selectively disables + DNSSEC validation for zones that are known to be + failing because of misconfiguration rather than + an attack. When data to be validated is + at or below an active NTA (and above any other + configured trust anchors), named will + abort the DNSSEC validation process and treat the data as + insecure rather than bogus. This continues until the + NTA's lifetime is elapsed. NTAs persist + across named restarts. +
+
+ For convenience, TTL-style time unit suffixes can be
+ used to specify the NTA lifetime in seconds, minutes
+ or hours. nta-lifetime defaults to
+ one hour. It cannot exceed one week.
+
+ Species how often to check whether negative + trust anchors added via rndc nta + are still necessary. +
++ A negative trust anchor is normally used when a + domain has stopped validating due to operator error; + it temporarily disables DNSSEC validation for that + domain. In the interest of ensuring that DNSSEC + validation is turned back on as soon as possible, + named will periodically send a + query to the domain, ignoring negative trust anchors, + to find out whether it can now be validated. If so, + the negative trust anchor is allowed to expire early. +
+
+ Validity checks can be disabled for an individual
+ NTA by using rndc nta -f, or
+ for all NTAs by setting nta-recheck
+ to zero.
+
+ For convenience, TTL-style time unit suffixes can be
+ used to specify the NTA recheck interval in seconds,
+ minutes or hours. The default is five minutes. It
+ cannot be longer than nta-lifetime
+ (which cannot be longer than a week).
+
+ Specifies a maximum permissible TTL value in seconds.
+ For convenience, TTL-style time unit suffixes may be
+ used to specify the maximum value.
+ When loading a zone file using a
+ masterfile-format of
+ text or raw,
+ any record encountered with a TTL higher than
+ max-zone-ttl will cause the zone to
+ be rejected.
+
+ This is useful in DNSSEC-signed zones because when
+ rolling to a new DNSKEY, the old key needs to remain
+ available until RRSIG records have expired from
+ caches. The max-zone-ttl option guarantees
+ that the largest TTL in the zone will be no higher
+ than the set value.
+
+ (NOTE: Because map-format files
+ load directly into memory, this option cannot be
+ used with them.)
+
+ The default value is unlimited.
+ A max-zone-ttl of zero is treated as
+ unlimited.
+
+ Specifies the TTL to be returned on stale answers.
+ The default is 1 second. The minimal allowed is
+ also 1 second; a value of 0 will be updated silently
+ to 1 second. For stale answers to be returned
+ max-stale-ttl must be set to a
+ non zero value and they must not have been disabled
+ by rndc.
+
+ Zones configured for dynamic DNS may use this + option to set the update method that will be used for + the zone serial number in the SOA record. +
++ With the default setting of + serial-update-method increment;, the + SOA serial number will be incremented by one each time + the zone is updated. +
++ When set to + serial-update-method unixtime;, the + SOA serial number will be set to the number of seconds + since the UNIX epoch, unless the serial number is + already greater than or equal to that value, in which + case it is simply incremented by one. +
++ When set to + serial-update-method date;, the + new SOA serial number will be the current date + in the form "YYYYMMDD", followed by two zeroes, + unless the existing serial number is already greater + than or equal to that value, in which case it is + incremented by one. +
+
+ If full, the server will collect
+ statistical data on all zones (unless specifically
+ turned off on a per-zone basis by specifying
+ zone-statistics terse or
+ zone-statistics none
+ in the zone statement).
+ The default is terse, providing
+ minimal statistics on zones (including name and
+ current serial number, but not query type
+ counters).
+
+ These statistics may be accessed via the + statistics-channel or + using rndc stats, which + will dump them to the file listed + in the statistics-file. See + also the section called “The Statistics File”. +
+
+ For backward compatibility with earlier versions
+ of BIND 9, the zone-statistics
+ option can also accept yes
+ or no; yes
+ has the same meaning as full.
+ As of BIND 9.10,
+ no has the same meaning
+ as none; previously, it
+ was the same as terse.
+
+ If yes and supported by the OS,
+ automatically rescan network interfaces when the interface
+ addresses are added or removed. The default is
+ yes.
+
+ Currently the OS needs to support routing sockets for + automatic-interface-scan to be + supported. +
+
+ If yes, then zones can be
+ added at runtime via rndc addzone.
+ The default is no.
+
+ Newly added zones' configuration parameters
+ are stored so that they can persist after the
+ server is restarted. The configuration information
+ is saved in a file called
+ viewname.nzfviewname.nzdviewname is the name of the
+ view, unless the view name contains characters that are
+ incompatible with use as a file name, in which case a
+ cryptographic hash of the view name is used instead.
+
+ Zones added at runtime will have their configuration + stored either in a new-zone file (NZF) or a new-zone + database (NZD) depending on whether + named was linked with + liblmdb at compile time. + See rndc(8) for further details + about rndc addzone. +
+
+ If yes, then the AA bit
+ is always set on NXDOMAIN responses, even if the server is
+ not actually
+ authoritative. The default is no;
+ this is
+ a change from BIND 8. If you
+ are using very old DNS software, you
+ may need to set it to yes.
+
+ This option was used in BIND + 8 to enable checking + for memory leaks on exit. BIND 9 ignores the option and always performs + the checks. +
+
+ Write memory statistics to the file specified by
+ memstatistics-file at exit.
+ The default is no unless
+ '-m record' is specified on the command line in
+ which case it is yes.
+
+ If yes, then the
+ server treats all zones as if they are doing zone transfers
+ across
+ a dial-on-demand dialup link, which can be brought up by
+ traffic
+ originating from this server. This has different effects
+ according
+ to zone type and concentrates the zone maintenance so that
+ it all
+ happens in a short interval, once every heartbeat-interval and
+ hopefully during the one call. It also suppresses some of
+ the normal
+ zone maintenance traffic. The default is no.
+
+ The dialup option + may also be specified in the view and + zone statements, + in which case it overrides the global dialup + option. +
++ If the zone is a master zone, then the server will send out a + NOTIFY + request to all the slaves (default). This should trigger the + zone serial + number check in the slave (providing it supports NOTIFY) + allowing the slave + to verify the zone while the connection is active. + The set of servers to which NOTIFY is sent can be controlled + by + notify and also-notify. +
++ If the + zone is a slave or stub zone, then the server will suppress + the regular + "zone up to date" (refresh) queries and only perform them + when the + heartbeat-interval expires in + addition to sending + NOTIFY requests. +
+
+ Finer control can be achieved by using
+ notify which only sends NOTIFY
+ messages,
+ notify-passive which sends NOTIFY
+ messages and
+ suppresses the normal refresh queries, refresh
+ which suppresses normal refresh processing and sends refresh
+ queries
+ when the heartbeat-interval
+ expires, and
+ passive which just disables normal
+ refresh
+ processing.
+
|
+ + dialup mode + + |
+
+ + normal refresh + + |
+
+ + heart-beat refresh + + |
+
+ + heart-beat notify + + |
+
|
+ no (default) + |
+
+ + yes + + |
+
+ + no + + |
+
+ + no + + |
+
|
+ yes + |
+
+ + no + + |
+
+ + yes + + |
+
+ + yes + + |
+
|
+ notify + |
+
+ + yes + + |
+
+ + no + + |
+
+ + yes + + |
+
|
+ refresh + |
+
+ + no + + |
+
+ + yes + + |
+
+ + no + + |
+
|
+ passive + |
+
+ + no + + |
+
+ + no + + |
+
+ + no + + |
+
|
+ notify-passive + |
+
+ + no + + |
+
+ + no + + |
+
+ + yes + + |
+
+ Note that normal NOTIFY processing is not affected by + dialup. +
+ ++ In BIND 8, this option + enabled simulating the obsolete DNS query type + IQUERY. BIND 9 never does + IQUERY simulation. +
+
+ This option is obsolete.
+ In BIND 8, fetch-glue yes
+ caused the server to attempt to fetch glue resource records
+ it
+ didn't have when constructing the additional
+ data section of a response. This is now considered a bad
+ idea
+ and BIND 9 never does it.
+
+ When the nameserver exits due receiving SIGTERM,
+ flush or do not flush any pending zone writes. The default
+ is
+ flush-zones-on-shutdown no.
+
+ When BIND is compiled with GeoIP support and configured
+ with "geoip" ACL elements, this option indicates whether
+ the EDNS Client Subnet option, if present in a request,
+ should be used for matching against the GeoIP database.
+ The default is
+ geoip-use-ecs yes.
+
+ This option was incorrectly implemented
+ in BIND 8, and is ignored by BIND 9.
+ To achieve the intended effect
+ of
+ has-old-clients yes, specify
+ the two separate options auth-nxdomain yes
+ and rfc2308-type1 no instead.
+
+ In BIND 8, this enables keeping of + statistics for every host that the name server interacts + with. + Not implemented in BIND 9. +
+
+ This option is obsolete.
+ It was used in BIND 8 to
+ determine whether a transaction log was
+ kept for Incremental Zone Transfer. BIND 9 maintains a transaction
+ log whenever possible. If you need to disable outgoing
+ incremental zone
+ transfers, use provide-ixfr no.
+
+ If yes, DNS name compression is
+ used in responses to regular queries (not including
+ AXFR or IXFR, which always uses compression). Setting
+ this option to no reduces CPU
+ usage on servers and may improve throughput. However,
+ it increases response size, which may cause more queries
+ to be processed using TCP; a server with compression
+ disabled is out of compliance with RFC 1123 Section
+ 6.1.3.2. The default is yes.
+
+ If set to yes, then when generating
+ responses the server will only add records to the authority
+ and additional data sections when they are required (e.g.
+ delegations, negative responses). This may improve the
+ performance of the server.
+
+ When set to no-auth, the
+ server will omit records from the authority section
+ unless they are required, but it may still add
+ records to the additional section. When set to
+ no-auth-recursive, this
+ is only done if the query is recursive. These
+ settings are useful when answering stub clients,
+ which usually ignore the authority section.
+ no-auth-recursive is
+ designed for mixed-mode servers which handle
+ both authoritative and recursive queries.
+
+ The default is yes.
+
+ When set to yes, a cache is
+ used to improve query performance when adding
+ address-type (A and AAAA) glue records to the
+ additional section of DNS response messages that
+ delegate to a child zone.
+
+ The glue cache uses memory proportional to the number
+ of delegations in the zone. The default setting is
+ yes, which improves performance
+ at the cost of increased memory usage for the zone. If
+ you don't want this, set it to no.
+
+ The glue cache is only used when
+ minimal-responses is also set
+ to yes.
+
+ If set to yes, then when
+ generating a positive response to a query of type
+ ANY over UDP, the server will reply with only one
+ of the RRsets for the query name, and its covering
+ RRSIGs if any, instead of replying with all known
+ RRsets for the name. Similarly, a query for type
+ RRSIG will be answered with the RRSIG records covering
+ only one type. This can reduce the impact of some kinds
+ of attack traffic, without harming legitimate
+ clients. (Note, however, that the RRset returned is the
+ first one found in the database; it is not necessarily
+ the smallest available RRset.)
+ Additionally, minimal-responses is
+ turned on for these queries, so no unnecessary records
+ will be added to the authority or additional sections.
+ The default is no.
+
+ This option was used in BIND 8 to allow + a domain name to have multiple CNAME records in violation of + the DNS standards. BIND 9.2 onwards + always strictly enforces the CNAME rules both in master + files and dynamic updates. +
+
+ If yes (the default),
+ DNS NOTIFY messages are sent when a zone the server is
+ authoritative for
+ changes, see the section called “Notify”. The messages are
+ sent to the
+ servers listed in the zone's NS records (except the master
+ server identified
+ in the SOA MNAME field), and to any servers listed in the
+ also-notify option.
+
+ If master-only, notifies are only
+ sent
+ for master zones.
+ If explicit, notifies are sent only
+ to
+ servers explicitly listed using also-notify.
+ If no, no notifies are sent.
+
+ The notify option may also be + specified in the zone + statement, + in which case it overrides the options notify statement. + It would only be necessary to turn off this option if it + caused slaves + to crash. +
+
+ If yes do not check the nameservers
+ in the NS RRset against the SOA MNAME. Normally a NOTIFY
+ message is not sent to the SOA MNAME (SOA ORIGIN) as it is
+ supposed to contain the name of the ultimate master.
+ Sometimes, however, a slave is listed as the SOA MNAME in
+ hidden master configurations and in that case you would
+ want the ultimate master to still send NOTIFY messages to
+ all the nameservers listed in the NS RRset.
+
+ If yes, and a
+ DNS query requests recursion, then the server will attempt
+ to do
+ all the work required to answer the query. If recursion is
+ off
+ and the server does not already know the answer, it will
+ return a
+ referral response. The default is
+ yes.
+ Note that setting recursion no does not prevent
+ clients from getting data from the server's cache; it only
+ prevents new data from being cached as an effect of client
+ queries.
+ Caching may still occur as an effect the server's internal
+ operation, such as NOTIFY address lookups.
+
+ If yes, then an empty EDNS(0)
+ NSID (Name Server Identifier) option is sent with all
+ queries to authoritative name servers during iterative
+ resolution. If the authoritative server returns an NSID
+ option in its response, then its contents are logged in
+ the resolver category at level
+ info.
+ The default is no.
+
+ This experimental option is obsolete. +
++ Require a valid server cookie before sending a full + response to a UDP request from a cookie aware client. + BADCOOKIE is sent if there is a bad or no existent + server cookie. +
+
+ If yes, then a COOKIE EDNS
+ option is sent along with the query. If the
+ resolver has previously talked to the server, the
+ COOKIE returned in the previous transaction is sent.
+ This is used by the server to determine whether
+ the resolver has talked to it before. A resolver
+ sending the correct COOKIE is assumed not to be an
+ off-path attacker sending a spoofed-source query;
+ the query is therefore unlikely to be part of a
+ reflection/amplification attack, so resolvers
+ sending a correct COOKIE option are not subject to
+ response rate limiting (RRL). Resolvers which
+ do not send a correct COOKIE option may be limited
+ to receiving smaller responses via the
+ nocookie-udp-size option.
+
+ Enable the returning of stale answers when the + nameservers for the zone are not answering. This + is off by default but can be enabled/disabled via + rndc server-stale on and + rndc server-stale off which + override the named.conf setting. rndc + server-stale reset will restore control + via named.conf. +
++ Sets the maximum size of UDP responses that will be + sent to queries without a valid server COOKIE. A value + below 128 will be silently raised to 128. The default + value is 4096, but the max-udp-size + option may further limit the response size. +
++ This experimental option is obsolete. +
++ Set the algorithm to be used when generating the + server cookie. One of "aes", "sha1" or "sha256". + The default is "aes" if supported by the cryptographic + library or otherwise "sha256". +
++ If set, this is a shared secret used for generating + and verifying EDNS COOKIE options + within an anycast cluster. If not set, the system + will generate a random secret at startup. The + shared secret is encoded as a hex string and needs + to be 128 bits for AES128, 160 bits for SHA1 and + 256 bits for SHA256. +
+
+ If there are multiple secrets specified, the first
+ one listed in named.conf is
+ used to generate new server cookies. The others
+ will only be used to verify returned cookies.
+
+ The EDNS Padding option is intended to improve + confidentiality when DNS queries are sent over an + encrypted channel by reducing the variability in + packet sizes. If a query: +
+
+ then the response is padded with an EDNS Padding option
+ to a multiple of block-size bytes.
+ If these conditions are not met, the response is not
+ padded.
+
+ If block-size is 0 or the ACL is
+ none;, then this feature is
+ disabled and no padding will occur; this is the
+ default. If block-size is greater
+ than 512, a warning is logged and the value is truncated
+ to 512. Block sizes are ordinarily expected to be powers
+ of two (for instance, 128), but this is not mandatory.
+
+ Setting this to yes will
+ cause the server to send NS records along with the SOA
+ record for negative
+ answers. The default is no.
+
+ Not yet implemented in BIND + 9. +
++ Causes named to send specially-formed + queries once per day to domains for which trust anchors + have been configured via trusted-keys, + managed-keys, + dnssec-validation auto, or + dnssec-lookaside auto. +
++ The query name used for these queries has the + form "_ta-xxxx(-xxxx)(...)".<domain>, where + each "xxxx" is a group of four hexadecimal digits + representing the key ID of a trusted DNSSEC key. + The key IDs for each domain are sorted smallest + to largest prior to encoding. The query type is NULL. +
++ By monitoring these queries, zone operators will + be able to see which resolvers have been updated to + trust a new key; this may help them decide when it + is safe to remove an old one. +
+
+ The default is yes.
+
+ This option is obsolete. + BIND 9 always allocates query + IDs from a pool. +
++ This option is obsolete. + If you need to disable IXFR to a particular server or + servers, see + the information on the provide-ixfr option + in the section called “server Statement Definition and + Usage”. + See also + the section called “Incremental Zone Transfers (IXFR)”. +
++ See the description of + provide-ixfr in + the section called “server Statement Definition and + Usage”. +
++ See the description of + request-ixfr in + the section called “server Statement Definition and + Usage”. +
++ See the description of + request-expire in + the section called “server Statement Definition and + Usage”. +
++ This option was used in BIND + 8 to make + the server treat carriage return ("\r") characters the same way + as a space or tab character, + to facilitate loading of zone files on a UNIX system that + were generated + on an NT or DOS machine. In BIND 9, both UNIX "\n" + and NT/DOS "\r\n" newlines + are always accepted, + and the option is ignored. +
+
+ If yes, then an
+ IPv4-mapped IPv6 address will match any address match
+ list entries that match the corresponding IPv4 address.
+
+ This option was introduced to work around a kernel quirk + in some operating systems that causes IPv4 TCP + connections, such as zone transfers, to be accepted on an + IPv6 socket using mapped addresses. This caused address + match lists designed for IPv4 to fail to match. However, + named now solves this problem + internally. The use of this option is discouraged. +
+
+ This option is only available when
+ BIND 9 is compiled with the
+ --enable-filter-aaaa option on the
+ "configure" command line. It is intended to help the
+ transition from IPv4 to IPv6 by not giving IPv6 addresses
+ to DNS clients unless they have connections to the IPv6
+ Internet. This is not recommended unless absolutely
+ necessary. The default is no.
+ The filter-aaaa-on-v4 option
+ may also be specified in view statements
+ to override the global filter-aaaa-on-v4
+ option.
+
+ If yes,
+ the DNS client is at an IPv4 address, in filter-aaaa,
+ and if the response does not include DNSSEC signatures,
+ then all AAAA records are deleted from the response.
+ This filtering applies to all responses and not only
+ authoritative responses.
+
+ If break-dnssec,
+ then AAAA records are deleted even when DNSSEC is enabled.
+ As suggested by the name, this makes the response not verify,
+ because the DNSSEC protocol is designed detect deletions.
+
+ This mechanism can erroneously cause other servers to + not give AAAA records to their clients. + A recursing server with both IPv6 and IPv4 network connections + that queries an authoritative server using this mechanism + via IPv4 will be denied AAAA records even if its client is + using IPv6. +
++ This mechanism is applied to authoritative as well as + non-authoritative records. + A client using IPv4 that is not allowed recursion can + erroneously be given AAAA records because the server is not + allowed to check for A records. +
++ Some AAAA records are given to IPv4 clients in glue records. + IPv4 clients that are servers can then erroneously + answer requests for AAAA records received via IPv4. +
+
+ Identical to filter-aaaa-on-v4,
+ except it filters AAAA responses to queries from IPv6
+ clients instead of IPv4 clients. To filter all
+ responses, set both options to yes.
+
+ When yes and the server loads a new
+ version of a master zone from its zone file or receives a
+ new version of a slave file via zone transfer, it will
+ compare the new version to the previous one and calculate
+ a set of differences. The differences are then logged in
+ the zone's journal file such that the changes can be
+ transmitted to downstream slaves as an incremental zone
+ transfer.
+
+ By allowing incremental zone transfers to be used for + non-dynamic zones, this option saves bandwidth at the + expense of increased CPU and memory consumption at the + master. + In particular, if the new version of a zone is completely + different from the previous one, the set of differences + will be of a size comparable to the combined size of the + old and new zone version, and the server will need to + temporarily allocate memory to hold this complete + difference set. +
+ixfr-from-differences + also accepts master and + slave at the view and options + levels which causes + ixfr-from-differences to be enabled for + all master or + slave zones respectively. + It is off by default. +
+
+ This should be set when you have multiple masters for a zone
+ and the
+ addresses refer to different machines. If yes, named will
+ not log
+ when the serial number on the master is less than what named
+ currently
+ has. The default is no.
+
+ Zones configured for dynamic DNS may use this + option to allow varying levels of automatic DNSSEC key + management. There are three possible settings: +
+
+ auto-dnssec allow; permits
+ keys to be updated and the zone fully re-signed
+ whenever the user issues the command rndc sign
+ zonename.
+
+ auto-dnssec maintain; includes the
+ above, but also automatically adjusts the zone's DNSSEC
+ keys on schedule, according to the keys' timing metadata
+ (see dnssec-keygen(8) and
+ dnssec-settime(8)). The command
+ rndc sign
+ zonename causes
+ named to load keys from the key
+ repository and sign the zone with all keys that are
+ active.
+ rndc loadkeys
+ zonename causes
+ named to load keys from the key
+ repository and schedule key maintenance events to occur
+ in the future, but it does not sign the full zone
+ immediately. Note: once keys have been loaded for a
+ zone the first time, the repository will be searched
+ for changes periodically, regardless of whether
+ rndc loadkeys is used. The recheck
+ interval is defined by
+ dnssec-loadkeys-interval.)
+
+ The default setting is auto-dnssec off. +
+
+ This indicates whether DNSSEC-related resource
+ records are to be returned by named.
+ If set to no,
+ named will not return DNSSEC-related
+ resource records unless specifically queried for.
+ The default is yes.
+
+ Enable DNSSEC validation in named.
+ Note dnssec-enable also needs to be
+ set to yes to be effective.
+ If set to no, DNSSEC validation
+ is disabled. If set to auto,
+ DNSSEC validation is enabled, and a default
+ trust-anchor for the DNS root zone is used. If set to
+ yes, DNSSEC validation is enabled,
+ but a trust anchor must be manually configured using
+ a trusted-keys or
+ managed-keys statement. The default
+ is yes.
+
+ Whenever the resolver sends out queries to an + EDNS-compliant server, it always sets the DO bit + indicating it can support DNSSEC responses even if + dnssec-validation is off. +
+
+ Accept expired signatures when verifying DNSSEC signatures.
+ The default is no.
+ Setting this option to yes
+ leaves named vulnerable to
+ replay attacks.
+
+ Specify whether query logging should be started when named + starts. + If querylog is not specified, + then the query logging + is determined by the presence of the logging category queries. +
++ This option is used to restrict the character set and syntax + of + certain domain names in master files and/or DNS responses + received + from the network. The default varies according to usage + area. For + master zones the default is fail. + For slave zones the default + is warn. + For answers received from the network (response) + the default is ignore. +
++ The rules for legal hostnames and mail domains are derived + from RFC 952 and RFC 821 as modified by RFC 1123. +
+check-names + applies to the owner names of A, AAAA and MX records. + It also applies to the domain names in the RDATA of NS, SOA, + MX, and SRV records. + It also applies to the RDATA of PTR records where the owner + name indicated that it is a reverse lookup of a hostname + (the owner name ends in IN-ADDR.ARPA, IP6.ARPA, or IP6.INT). +
++ Check master zones for records that are treated as different + by DNSSEC but are semantically equal in plain DNS. The + default is to warn. Other possible + values are fail and + ignore. +
++ Check whether the MX record appears to refer to a IP address. + The default is to warn. Other possible + values are fail and + ignore. +
++ This option is used to check for non-terminal wildcards. + The use of non-terminal wildcards is almost always as a + result of a failure + to understand the wildcard matching algorithm (RFC 1034). + This option + affects master zones. The default (yes) is to check + for non-terminal wildcards and issue a warning. +
++ Perform post load zone integrity checks on master + zones. This checks that MX and SRV records refer + to address (A or AAAA) records and that glue + address records exist for delegated zones. For + MX and SRV records only in-zone hostnames are + checked (for out-of-zone hostnames use + named-checkzone). + For NS records only names below top of zone are + checked (for out-of-zone names and glue consistency + checks use named-checkzone). + The default is yes. +
++ The use of the SPF record for publishing Sender + Policy Framework is deprecated as the migration + from using TXT records to SPF records was abandoned. + Enabling this option also checks that a TXT Sender + Policy Framework record exists (starts with "v=spf1") + if there is an SPF record. Warnings are emitted if the + TXT record does not exist and can be suppressed with + check-spf. +
++ If check-integrity is set then + fail, warn or ignore MX records that refer + to CNAMES. The default is to warn. +
++ If check-integrity is set then + fail, warn or ignore SRV records that refer + to CNAMES. The default is to warn. +
++ When performing integrity checks, also check that + sibling glue exists. The default is yes. +
++ If check-integrity is set then + check that there is a TXT Sender Policy Framework + record present (starts with "v=spf1") if there is an + SPF record present. The default is + warn. +
++ When returning authoritative negative responses to + SOA queries set the TTL of the SOA record returned in + the authority section to zero. + The default is yes. +
++ When caching a negative response to a SOA query + set the TTL to zero. + The default is no. +
+
+ When set to the default value of yes,
+ check the KSK bit in each key to determine how the key
+ should be used when generating RRSIGs for a secure zone.
+
+ Ordinarily, zone-signing keys (that is, keys without the
+ KSK bit set) are used to sign the entire zone, while
+ key-signing keys (keys with the KSK bit set) are only
+ used to sign the DNSKEY RRset at the zone apex.
+ However, if this option is set to no,
+ then the KSK bit is ignored; KSKs are treated as if they
+ were ZSKs and are used to sign the entire zone. This is
+ similar to the dnssec-signzone -z
+ command line option.
+
+ When this option is set to yes, there
+ must be at least two active keys for every algorithm
+ represented in the DNSKEY RRset: at least one KSK and one
+ ZSK per algorithm. If there is any algorithm for which
+ this requirement is not met, this option will be ignored
+ for that algorithm.
+
+ When this option and update-check-ksk
+ are both set to yes, only key-signing
+ keys (that is, keys with the KSK bit set) will be used
+ to sign the DNSKEY RRset at the zone apex. Zone-signing
+ keys (keys without the KSK bit set) will be used to sign
+ the remainder of the zone, but not the DNSKEY RRset.
+ This is similar to the
+ dnssec-signzone -x command line option.
+
+ The default is no. If
+ update-check-ksk is set to
+ no, this option is ignored.
+
+ Try to refresh the zone using TCP if UDP queries fail. + For BIND 8 compatibility, the default is + yes. +
++ Allow a dynamic zone to transition from secure to + insecure (i.e., signed to unsigned) by deleting all + of the DNSKEY records. The default is no. + If set to yes, and if the DNSKEY RRset + at the zone apex is deleted, all RRSIG and NSEC records + will be removed from the zone as well. +
++ If the zone uses NSEC3, then it is also necessary to + delete the NSEC3PARAM RRset from the zone apex; this will + cause the removal of all corresponding NSEC3 records. + (It is expected that this requirement will be eliminated + in a future release.) +
++ Note that if a zone has been configured with + auto-dnssec maintain and the + private keys remain accessible in the key repository, + then the zone will be automatically signed again the + next time named is started. +
++ Synthesize answers from cached NSEC, NSEC3 and + other RRsets that have been proved to be correct + using DNSSEC. The default is yes. +
++ Note: +
++ DNSSEC validation must be enabled for this + option to be effective. +
++ This initial implementation only covers + NXDOMAIN synthesis from NSEC records. + Synthesis of NODATA and wildcard responses + is also planned, as is synthesis from NSEC3 + records. All of these will be controlled + by synth-from-dnssec. +
++
++ The forwarding facility can be used to create a large site-wide + cache on a few servers, reducing traffic over links to external + name servers. It can also be used to allow queries by servers that + do not have direct access to the Internet, but wish to look up + exterior + names anyway. Forwarding occurs only on those queries for which + the server is not authoritative and does not have the answer in + its cache. +
+ +
+ This option is only meaningful if the
+ forwarders list is not empty. A value of first,
+ the default, causes the server to query the forwarders
+ first — and
+ if that doesn't answer the question, the server will then
+ look for
+ the answer itself. If only is
+ specified, the
+ server will only query the forwarders.
+
+ Specifies the IP addresses to be used + for forwarding. The default is the empty list (no + forwarding). +
++ Forwarding can also be configured on a per-domain basis, allowing + for the global forwarding options to be overridden in a variety + of ways. You can set particular domains to use different + forwarders, + or have a different forward only/first behavior, + or not forward at all, see the section called “zone + Statement Grammar”. +
++ Dual-stack servers are used as servers of last resort to work + around + problems in reachability due the lack of support for either IPv4 + or IPv6 + on the host machine. +
+ ++ Specifies host names or addresses of machines with access to + both IPv4 and IPv6 transports. If a hostname is used, the + server must be able + to resolve the name using only the transport it has. If the + machine is dual + stacked, then the dual-stack-servers have no effect unless + access to a transport has been disabled on the command line + (e.g. named -4). +
++ Access to the server can be restricted based on the IP address + of the requesting system. See the section called “Address Match Lists” for + details on how to specify IP address lists. +
+ ++ Specifies which hosts are allowed to + notify this server, a slave, of zone changes in addition + to the zone masters. + allow-notify may also be + specified in the + zone statement, in which case + it overrides the + options allow-notify + statement. It is only meaningful + for a slave zone. If not specified, the default is to + process notify messages + only from a zone's master. +
++ Specifies which hosts are allowed to ask ordinary + DNS questions. allow-query may + also be specified in the zone + statement, in which case it overrides the + options allow-query statement. + If not specified, the default is to allow queries + from all hosts. +
++ allow-query-cache is now + used to specify access to the cache. +
++ Specifies which local addresses can accept ordinary + DNS questions. This makes it possible, for instance, + to allow queries on internal-facing interfaces but + disallow them on external-facing ones, without + necessarily knowing the internal network's addresses. +
++ Note that allow-query-on is only + checked for queries that are permitted by + allow-query. A query must be + allowed by both ACLs, or it will be refused. +
++ allow-query-on may + also be specified in the zone + statement, in which case it overrides the + options allow-query-on statement. +
++ If not specified, the default is to allow queries + on all addresses. +
++ allow-query-cache is + used to specify access to the cache. +
++ Specifies which hosts are allowed to get answers + from the cache. If allow-query-cache + is not set then allow-recursion + is used if set, otherwise allow-query + is used if set unless recursion no; is + set in which case none; is used, + otherwise the default (localnets; + localhost;) is used. +
++ Specifies which local addresses can give answers + from the cache. If not specified, the default is + to allow cache queries on any address, + localnets and + localhost. +
++ Specifies which hosts are allowed to make recursive + queries through this server. If + allow-recursion is not set + then allow-query-cache is + used if set, otherwise allow-query + is used if set, otherwise the default + (localnets; + localhost;) is used. +
++ Specifies which local addresses can accept recursive + queries. If not specified, the default is to allow + recursive queries on all addresses. +
++ Specifies which hosts are allowed to + submit Dynamic DNS updates for master zones. The default is + to deny + updates from all hosts. Note that allowing updates based + on the requestor's IP address is insecure; see + the section called “Dynamic Update Security” for details. +
+
+ Specifies which hosts are allowed to
+ submit Dynamic DNS updates to slave zones to be forwarded to
+ the
+ master. The default is { none; },
+ which
+ means that no update forwarding will be performed. To
+ enable
+ update forwarding, specify
+ allow-update-forwarding { any; };.
+ Specifying values other than { none; } or
+ { any; } is usually
+ counterproductive, since
+ the responsibility for update access control should rest
+ with the
+ master server, not the slaves.
+
+ Note that enabling the update forwarding feature on a slave + server + may expose master servers relying on insecure IP address + based + access control to attacks; see the section called “Dynamic Update Security” + for more details. +
++ This option was introduced for the smooth transition from + AAAA + to A6 and from "nibble labels" to binary labels. + However, since both A6 and binary labels were then + deprecated, + this option was also deprecated. + It is now ignored with some warning messages. +
++ Specifies which hosts are allowed to + receive zone transfers from the server. allow-transfer may + also be specified in the zone + statement, in which + case it overrides the options allow-transfer statement. + If not specified, the default is to allow transfers to all + hosts. +
+
+ Specifies a list of addresses that the
+ server will not accept queries from or use to resolve a
+ query. Queries
+ from these addresses will not be responded to. The default
+ is none.
+
+ Specifies a list of addresses to which
+ filter-aaaa-on-v4
+ and filter-aaaa-on-v6
+ apply. The default is any.
+
+ Specifies a list of addresses to which the server
+ will send responses to TCP queries in the same order
+ in which they were received. This disables the
+ processing of TCP queries in parallel. The default
+ is none.
+
+ Specifies a list of addresses which require responses + to use case-insensitive compression. This ACL can be + used when named needs to work with + clients that do not comply with the requirement in RFC + 1034 to use case-insensitive name comparisons when + checking for matching domain names. +
++ If left undefined, the ACL defaults to + none: case-insensitive compression + will be used for all clients. If the ACL is defined and + matches a client, then case will be ignored when + compressing domain names in DNS responses sent to that + client. +
++ This can result in slightly smaller responses: if + a response contains the names "example.com" and + "example.COM", case-insensitive compression would treat + the second one as a duplicate. It also ensures + that the case of the query name exactly matches the + case of the owner names of returned records, rather + than matching the case of the records entered in + the zone file. This allows responses to exactly + match the query, which is required by some clients + due to incorrect use of case-sensitive comparisons. +
++ Case-insensitive compression is always + used in AXFR and IXFR responses, regardless of whether + the client matches this ACL. +
++ There are circumstances in which named + will not preserve the case of owner names of records: + if a zone file defines records of different types with + the same name, but the capitalization of the name is + different (e.g., "www.example.com/A" and + "WWW.EXAMPLE.COM/AAAA"), then all responses for that + name will use the first version + of the name that was used in the zone file. This + limitation may be addressed in a future release. However, + domain names specified in the rdata of resource records + (i.e., records of type NS, MX, CNAME, etc) will always + have their case preserved unless the client matches this + ACL. +
+
+ The amount of time in milliseconds that the resolver
+ will spend attempting to resolve a recursive
+ query before failing. The default and minimum
+ is 10000 and the maximum is
+ 30000. Setting it to
+ 0 will result in the default
+ being used.
+
+ This value was originally specified in seconds. + Values less than or equal to 300 will be be treated + as seconds and converted to milliseconds before + applying the above limits. +
+
+ The interfaces and ports that the server will answer queries
+ from may be specified using the listen-on option. listen-on takes
+ an optional port and an address_match_list
+ of IPv4 addresses. (IPv6 addresses are ignored, with a
+ logged warning.)
+ The server will listen on all interfaces allowed by the address
+ match list. If a port is not specified, port 53 will be used.
+
+ Multiple listen-on statements are + allowed. + For example, +
+ +listen-on { 5.6.7.8; };
+listen-on port 1234 { !1.2.3.4; 1.2/16; };
+
+
+ + will enable the name server on port 53 for the IP address + 5.6.7.8, and on port 1234 of an address on the machine in net + 1.2 that is not 1.2.3.4. +
+ ++ If no listen-on is specified, the + server will listen on port 53 on all IPv4 interfaces. +
+ ++ The listen-on-v6 option is used to + specify the interfaces and the ports on which the server will + listen for incoming queries sent using IPv6. If not specified, + the server will listen on port 53 on all IPv6 interfaces. +
+ ++ When
+{ any; }
+ is
+ specified
+ as the address_match_list for the
+ listen-on-v6 option,
+ the server does not bind a separate socket to each IPv6 interface
+ address as it does for IPv4 if the operating system has enough API
+ support for IPv6 (specifically if it conforms to RFC 3493 and RFC
+ 3542).
+ Instead, it listens on the IPv6 wildcard address.
+ If the system only has incomplete API support for IPv6, however,
+ the behavior is the same as that for IPv4.
+
+ A list of particular IPv6 addresses can also be specified, in + which case + the server listens on a separate socket for each specified + address, + regardless of whether the desired API is supported by the system. + IPv4 addresses specified in listen-on-v6 + will be ignored, with a logged warning. +
+ ++ Multiple listen-on-v6 options can + be used. + For example, +
+ +listen-on-v6 { any; };
+listen-on-v6 port 1234 { !2001:db8::/32; any; };
+
+
+ + will enable the name server on port 53 for any IPv6 addresses + (with a single wildcard socket), + and on port 1234 of IPv6 addresses that is not in the prefix + 2001:db8::/32 (with separate sockets for each matched address.) +
+ ++ To make the server not listen on any IPv6 address, use +
+ +listen-on-v6 { none; };
+
+
+ + If the server doesn't know the answer to a question, it will + query other name servers. query-source specifies + the address and port used for such queries. For queries sent over + IPv6, there is a separate query-source-v6 option. + If address is * (asterisk) or is omitted, + a wildcard IP address (INADDR_ANY) + will be used. +
+ ++ If port is * or is omitted, + a random port number from a pre-configured + range is picked up and will be used for each query. + The port range(s) is that specified in + the use-v4-udp-ports (for IPv4) + and use-v6-udp-ports (for IPv6) + options, excluding the ranges specified in + the avoid-v4-udp-ports + and avoid-v6-udp-ports options, respectively. +
+ ++ The defaults of the query-source and + query-source-v6 options + are: +
+ +query-source address * port *; +query-source-v6 address * port *; ++ +
+ If use-v4-udp-ports or + use-v6-udp-ports is unspecified, + named will check if the operating + system provides a programming interface to retrieve the + system's default range for ephemeral ports. + If such an interface is available, + named will use the corresponding system + default range; otherwise, it will use its own defaults: +
+ +use-v4-udp-ports { range 1024 65535; };
+use-v6-udp-ports { range 1024 65535; };
+
+
+ + Note: make sure the ranges be sufficiently large for + security. A desirable size depends on various parameters, + but we generally recommend it contain at least 16384 ports + (14 bits of entropy). + Note also that the system's default range when used may be + too small for this purpose, and that the range may even be + changed while named is running; the new + range will automatically be applied when named + is reloaded. + It is encouraged to + configure use-v4-udp-ports and + use-v6-udp-ports explicitly so that the + ranges are sufficiently large and are reasonably + independent from the ranges used by other applications. +
+ ++ Note: the operational configuration + where named runs may prohibit the use + of some ports. For example, UNIX systems will not allow + named running without a root privilege + to use ports less than 1024. + If such ports are included in the specified (or detected) + set of query ports, the corresponding query attempts will + fail, resulting in resolution failures or delay. + It is therefore important to configure the set of ports + that can be safely used in the expected operational environment. +
+ ++ The defaults of the avoid-v4-udp-ports and + avoid-v6-udp-ports options + are: +
+ +avoid-v4-udp-ports {};
+avoid-v6-udp-ports {};
+
+
+ + Note: BIND 9.5.0 introduced + the use-queryport-pool + option to support a pool of such random ports, but this + option is now obsolete because reusing the same ports in + the pool may not be sufficiently secure. + For the same reason, it is generally strongly discouraged to + specify a particular port for the + query-source or + query-source-v6 options; + it implicitly disables the use of randomized port numbers. +
+ ++ This option is obsolete. +
++ This option is obsolete. +
++ This option is obsolete. +
++ The address specified in the query-source option + is used for both UDP and TCP queries, but the port applies only + to UDP queries. TCP queries always use a random + unprivileged port. +
++ Solaris 2.5.1 and earlier does not support setting the source + address for TCP sockets. +
++ See also transfer-source and + notify-source. +
++ BIND has mechanisms in place to + facilitate zone transfers + and set limits on the amount of load that transfers place on the + system. The following options apply to zone transfers. +
+ ++ Defines a global list of IP addresses of name servers + that are also sent NOTIFY messages whenever a fresh copy of + the + zone is loaded, in addition to the servers listed in the + zone's NS records. + This helps to ensure that copies of the zones will + quickly converge on stealth servers. + Optionally, a port may be specified with each + also-notify address to send + the notify messages to a port other than the + default of 53. + An optional TSIG key can also be specified with each + address to cause the notify messages to be signed; this + can be useful when sending notifies to multiple views. + In place of explicit addresses, one or more named + masters lists can be used. +
++ If an also-notify list + is given in a zone statement, + it will override + the options also-notify + statement. When a zone notify + statement + is set to no, the IP + addresses in the global also-notify list will + not be sent NOTIFY messages for that zone. The default is + the empty + list (no global notification list). +
++ Inbound zone transfers running longer than + this many minutes will be terminated. The default is 120 + minutes + (2 hours). The maximum value is 28 days (40320 minutes). +
++ Inbound zone transfers making no progress + in this many minutes will be terminated. The default is 60 + minutes + (1 hour). The maximum value is 28 days (40320 minutes). +
++ Outbound zone transfers running longer than + this many minutes will be terminated. The default is 120 + minutes + (2 hours). The maximum value is 28 days (40320 minutes). +
++ Outbound zone transfers making no progress + in this many minutes will be terminated. The default is 60 + minutes (1 + hour). The maximum value is 28 days (40320 minutes). +
++ The rate at which NOTIFY requests will be sent + during normal zone maintenance operations. (NOTIFY + requests due to initial zone loading are subject + to a separate rate limit; see below.) The default is + 20 per second. + The lowest possible rate is one per second; when set + to zero, it will be silently raised to one. +
++ The rate at which NOTIFY requests will be sent + when the name server is first starting up, or when + zones have been newly added to the nameserver. + The default is 20 per second. + The lowest possible rate is one per second; when set + to zero, it will be silently raised to one. +
++ Slave servers will periodically query master + servers to find out if zone serial numbers have + changed. Each such query uses a minute amount of + the slave server's network bandwidth. To limit + the amount of bandwidth used, BIND 9 limits the + rate at which queries are sent. The value of the + serial-query-rate option, an + integer, is the maximum number of queries sent + per second. The default is 20 per second. + The lowest possible rate is one per second; when set + to zero, it will be silently raised to one. +
++ In BIND 8, the serial-queries + option + set the maximum number of concurrent serial number queries + allowed to be outstanding at any given time. + BIND 9 does not limit the number of outstanding + serial queries and ignores the serial-queries option. + Instead, it limits the rate at which the queries are sent + as defined using the serial-query-rate option. +
++ Zone transfers can be sent using two different formats, + one-answer and + many-answers. + The transfer-format option is used + on the master server to determine which format it sends. + one-answer uses one DNS message per + resource record transferred. + many-answers packs as many resource + records as possible into a message. + many-answers is more efficient, but is + only supported by relatively new slave servers, + such as BIND 9, BIND + 8.x and BIND 4.9.5 onwards. + The many-answers format is also supported by + recent Microsoft Windows nameservers. + The default is many-answers. + transfer-format may be overridden on a + per-server basis by using the server + statement. +
+ ++ This is an upper bound on the uncompressed size of DNS + messages used in zone transfers over TCP. If a message + grows larger than this size, additional messages will be + used to complete the zone transfer. (Note, however, + that this is a hint, not a hard limit; if a message + contains a single resource record whose RDATA does not + fit within the size limit, a larger message will be + permitted so the record can be transferred.) +
+
+ Valid values are between 512 and 65535 octets, and any
+ values outside that range will be adjusted to the nearest
+ value within it. The default is 20480,
+ which was selected to improve message compression:
+ most DNS messages of this size will compress to less
+ than 16536 bytes. Larger messages cannot be compressed
+ as effectively, because 16536 is the largest permissible
+ compression offset pointer in a DNS message.
+
+ This option is mainly intended for server testing; + there is rarely any benefit in setting a value other + than the default. +
+
+ The maximum number of inbound zone transfers
+ that can be running concurrently. The default value is 10.
+ Increasing transfers-in may
+ speed up the convergence
+ of slave zones, but it also may increase the load on the
+ local system.
+
+ The maximum number of outbound zone transfers
+ that can be running concurrently. Zone transfer requests in
+ excess
+ of the limit will be refused. The default value is 10.
+
+ The maximum number of inbound zone transfers
+ that can be concurrently transferring from a given remote
+ name server.
+ The default value is 2.
+ Increasing transfers-per-ns
+ may
+ speed up the convergence of slave zones, but it also may
+ increase
+ the load on the remote name server. transfers-per-ns may
+ be overridden on a per-server basis by using the transfers phrase
+ of the server statement.
+
transfer-source + determines which local address will be bound to IPv4 + TCP connections used to fetch zones transferred + inbound by the server. It also determines the + source IPv4 address, and optionally the UDP port, + used for the refresh queries and forwarded dynamic + updates. If not set, it defaults to a system + controlled value which will usually be the address + of the interface "closest to" the remote end. This + address must appear in the remote end's + allow-transfer option for the + zone being transferred, if one is specified. This + statement sets the + transfer-source for all zones, + but can be overridden on a per-view or per-zone + basis by including a + transfer-source statement within + the view or + zone block in the configuration + file. +
++ Solaris 2.5.1 and earlier does not support setting the + source address for TCP sockets. +
++ The same as transfer-source, + except zone transfers are performed using IPv6. +
++ An alternate transfer source if the one listed in + transfer-source fails and + use-alt-transfer-source is + set. +
++ If you do not wish the alternate transfer source + to be used, you should set + use-alt-transfer-source + appropriately and you should not depend upon + getting an answer back to the first refresh + query. +
++ An alternate transfer source if the one listed in + transfer-source-v6 fails and + use-alt-transfer-source is + set. +
++ Use the alternate transfer sources or not. If views are + specified this defaults to no + otherwise it defaults to + yes (for BIND 8 + compatibility). +
+notify-source + determines which local source address, and + optionally UDP port, will be used to send NOTIFY + messages. This address must appear in the slave + server's masters zone clause or + in an allow-notify clause. This + statement sets the notify-source + for all zones, but can be overridden on a per-zone or + per-view basis by including a + notify-source statement within + the zone or + view block in the configuration + file. +
++ Solaris 2.5.1 and earlier does not support setting the + source address for TCP sockets. +
++ Like notify-source, + but applies to notify messages sent to IPv6 addresses. +
++ use-v4-udp-ports, + avoid-v4-udp-ports, + use-v6-udp-ports, and + avoid-v6-udp-ports + specify a list of IPv4 and IPv6 UDP ports that will be + used or not used as source ports for UDP messages. + See the section called “Query Address” about how the + available ports are determined. + For example, with the following configuration +
+ +
+use-v6-udp-ports { range 32768 65535; };
+avoid-v6-udp-ports { 40000; range 50000 60000; };
+
+
+ + UDP ports of IPv6 messages sent + from named will be in one + of the following ranges: 32768 to 39999, 40001 to 49999, + and 60001 to 65535. +
+ ++ avoid-v4-udp-ports and + avoid-v6-udp-ports can be used + to prevent named from choosing as its random source port a + port that is blocked by your firewall or a port that is + used by other applications; + if a query went out with a source port blocked by a + firewall, the + answer would not get by the firewall and the name server would + have to query again. + Note: the desired range can also be represented only with + use-v4-udp-ports and + use-v6-udp-ports, and the + avoid- options are redundant in that + sense; they are provided for backward compatibility and + to possibly simplify the port specification. +
++ The server's usage of many system resources can be limited. + Scaled values are allowed when specifying resource limits. For + example, 1G can be used instead of + 1073741824 to specify a limit of + one + gigabyte. unlimited requests + unlimited use, or the + maximum available amount. default + uses the limit + that was in force when the server was started. See the description + of size_spec in the section called “Configuration File Elements”. +
+ ++ The following options set operating system resource limits for + the name server process. Some operating systems don't support + some or + any of the limits. On such systems, a warning will be issued if + the + unsupported limit is used. +
+ +
+ The maximum size of a core dump. The default
+ is default.
+
+ The maximum amount of data memory the server
+ may use. The default is default.
+ This is a hard limit on server memory usage.
+ If the server attempts to allocate memory in excess of this
+ limit, the allocation will fail, which may in turn leave
+ the server unable to perform DNS service. Therefore,
+ this option is rarely useful as a way of limiting the
+ amount of memory used by the server, but it can be used
+ to raise an operating system data size limit that is
+ too small by default. If you wish to limit the amount
+ of memory used by the server, use the
+ max-cache-size and
+ recursive-clients
+ options instead.
+
+ The maximum number of files the server
+ may have open concurrently. The default is unlimited.
+
+ The maximum amount of stack memory the server
+ may use. The default is default.
+
+ The following options set limits on the server's + resource consumption that are enforced internally by the + server rather than the operating system. +
+ ++ This option is obsolete; it is accepted + and ignored for BIND 8 compatibility. The option + max-journal-size performs a + similar function in BIND 9. +
+
+ Sets a maximum size for each journal file (see
+ the section called “The journal file”), expressed in bytes
+ or, if followed by an optional unit suffix ('k',
+ 'm', or 'g'), in kilobytes, megabytes, or gigabytes.
+ When the journal file approaches the specified size,
+ some of the oldest transactions in the journal
+ will be automatically removed. The largest
+ permitted value is 2 gigabytes. Very small
+ values are rounded up to 4096 bytes. You
+ can specify unlimited, which
+ also means 2 gigabytes. If you set the limit to
+ default or leave it unset, the
+ journal is allowed to grow up to twice as large as
+ the zone. (There is little benefit in storing
+ larger journals.)
+
+ This option may also be set on a per-zone basis. +
++ The maximum number of records permitted in a zone. + The default is zero which means unlimited. +
++ In BIND 8, specifies the maximum number of host statistics + entries to be kept. + Not implemented in BIND 9. +
+
+ The maximum number ("hard quota") of simultaneous
+ recursive lookups the server will perform on behalf
+ of clients. The default is
+ 1000. Because each recursing
+ client uses a fair
+ bit of memory (on the order of 20 kilobytes), the
+ value of the
+ recursive-clients option may
+ have to be decreased on hosts with limited memory.
+
+ recursive-clients defines a "hard
+ quota" limit for pending recursive clients: when more
+ clients than this are pending, new incoming requests
+ will not be accepted, and for each incoming request
+ a previous pending request will also be dropped.
+
+ A "soft quota" is also set. When this lower
+ quota is exceeded, incoming requests are accepted, but
+ for each one, a pending request will be dropped.
+ If recursive-clients is greater than
+ 1000, the soft quota is set to
+ recursive-clients minus 100;
+ otherwise it is set to 90% of
+ recursive-clients.
+
+ The maximum number of simultaneous client TCP
+ connections that the server will accept.
+ The default is 150.
+
These set the + initial value (minimum) and maximum number of recursive + simultaneous clients for any given query + (<qname,qtype,qclass>) that the server will accept + before dropping additional clients. named will attempt to + self tune this value and changes will be logged. The + default values are 10 and 100. +
++ This value should reflect how many queries come in for + a given name in the time it takes to resolve that name. + If the number of queries exceed this value, named will + assume that it is dealing with a non-responsive zone + and will drop additional queries. If it gets a response + after dropping queries, it will raise the estimate. The + estimate will then be lowered in 20 minutes if it has + remained unchanged. +
++ If clients-per-query is set to zero, + then there is no limit on the number of clients per query + and no queries will be dropped. +
++ If max-clients-per-query is set to zero, + then there is no upper bound other than imposed by + recursive-clients. +
+
+ The maximum number of simultaneous iterative
+ queries to any one domain that the server will
+ permit before blocking new queries for data
+ in or beneath that zone.
+ This value should reflect how many fetches would
+ normally be sent to any one zone in the time it
+ would take to resolve them. It should be smaller
+ than recursive-clients.
+
+ When many clients simultaneously query for the
+ same name and type, the clients will all be attached
+ to the same fetch, up to the
+ max-clients-per-query limit,
+ and only one iterative query will be sent.
+ However, when clients are simultaneously
+ querying for different names
+ or types, multiple queries will be sent and
+ max-clients-per-query is not
+ effective as a limit.
+
+ Optionally, this value may be followed by the keyword
+ drop or fail,
+ indicating whether queries which exceed the fetch
+ quota for a zone will be dropped with no response,
+ or answered with SERVFAIL. The default is
+ drop.
+
+ If fetches-per-zone is set to zero, + then there is no limit on the number of fetches per query + and no queries will be dropped. The default is zero. +
+
+ The current list of active fetches can be dumped by
+ running rndc recursing. The list
+ includes the number of active fetches for each
+ domain and the number of queries that have been
+ passed or dropped as a result of the
+ fetches-per-zone limit. (Note:
+ these counters are not cumulative over time; whenever
+ the number of active fetches for a domain drops to
+ zero, the counter for that domain is deleted, and the
+ next time a fetch is sent to that domain, it is
+ recreated with the counters set to zero.)
+
+ The maximum number of simultaneous iterative
+ queries that the server will allow to be sent to
+ a single upstream name server before blocking
+ additional queries.
+ This value should reflect how many fetches would
+ normally be sent to any one server in the time it
+ would take to resolve them. It should be smaller
+ than recursive-clients.
+
+ Optionally, this value may be followed by the keyword
+ drop or fail,
+ indicating whether queries will be dropped with no
+ response, or answered with SERVFAIL, when all of the
+ servers authoritative for a zone are found to have
+ exceeded the per-server quota. The default is
+ fail.
+
+ If fetches-per-server is set to zero, + then there is no limit on the number of fetches per query + and no queries will be dropped. The default is zero. +
++ The fetches-per-server quota is + dynamically adjusted in response to detected + congestion. As queries are sent to a server + and are either answered or time out, an + exponentially weighted moving average is calculated + of the ratio of timeouts to responses. If the + current average timeout ratio rises above a "high" + threshold, then fetches-per-server + is reduced for that server. If the timeout ratio + drops below a "low" threshold, then + fetches-per-server is increased. + The fetch-quota-params options + can be used to adjust the parameters for this + calculation. +
+
+ Sets the parameters to use for dynamic resizing of
+ the fetches-per-server quota in
+ response to detected congestion.
+
+ The first argument is an integer value indicating + how frequently to recalculate the moving average + of the ratio of timeouts to responses for each + server. The default is 100, meaning we recalculate + the average ratio after every 100 queries have either + been answered or timed out. +
++ The remaining three arguments represent the "low" + threshold (defaulting to a timeout ratio of 0.1), + the "high" threshold (defaulting to a timeout + ratio of 0.3), and the discount rate for + the moving average (defaulting to 0.7). + A higher discount rate causes recent events to + weigh more heavily when calculating the moving + average; a lower discount rate causes past + events to weigh more heavily, smoothing out + short-term blips in the timeout ratio. + These arguments are all fixed-point numbers with + precision of 1/100: at most two places after + the decimal point are significant. +
+
+ The number of file descriptors reserved for TCP, stdio,
+ etc. This needs to be big enough to cover the number of
+ interfaces named listens on, tcp-clients as well as
+ to provide room for outgoing TCP queries and incoming zone
+ transfers. The default is 512.
+ The minimum value is 128 and the
+ maximum value is 128 less than
+ maxsockets (-S). This option may be removed in the future.
+
+ This option has little effect on Windows. +
+
+ The maximum amount of memory to use for the
+ server's cache, in bytes or % of total physical memory.
+ When the amount of data in the cache
+ reaches this limit, the server will cause records to
+ expire prematurely based on an LRU based strategy so
+ that the limit is not exceeded.
+ The keyword unlimited,
+ or the value 0, will place no limit on cache size;
+ records will be purged from the cache only when their
+ TTLs expire.
+ Any positive values less than 2MB will be ignored
+ and reset to 2MB.
+ In a server with multiple views, the limit applies
+ separately to the cache of each view.
+ The default is 90%.
+ On systems where detection of amount of physical
+ memory is not supported values represented as %
+ fall back to unlimited.
+ Note that the detection of physical memory is done only
+ once at startup, so named will not
+ adjust the cache size if the amount of physical memory
+ is changed during runtime.
+
+ The listen queue depth. The default and minimum is 10. + If the kernel supports the accept filter "dataready" this + also controls how + many TCP connections that will be queued in kernel space + waiting for + some data before being passed to accept. Nonzero values + less than 10 will be silently raised. A value of 0 may also + be used; on most platforms this sets the listen queue + length to a system-defined default value. +
++ The amount of time (in units of 100 milliseconds) the + server waits on a new TCP connection for the first message + from the client. The default is 300 (30 seconds), + the minimum is 25 (2.5 seconds), and the maximum is + 1200 (two minutes). Values above the maximum or below + the minimum will be adjusted with a logged warning. + (Note: This value must be greater than the expected + round trip delay time; otherwise no client will ever + have enough time to submit a message.) + This value can be updated at runtime by using + rndc tcp-timeouts. +
++ The amount of time (in units of 100 milliseconds) the + server waits on an idle TCP conenction before closing + it when the client is not using the EDNS TCP keepalive + option. The default is 300 (30 seconds), the maximum + is 1200 (two minutes), and the minimum is 1 (one tenth + of a second). Values above the maximum or below the minimum + will be adjusted with a logged warning. + See tcp-keepalive-timeout + for clients using the EDNS TCP keepalive option. + This value can be updated at runtime by using + rndc tcp-timeouts. +
++ The amount of time (in units of 100 milliseconds) the + server waits on an idle TCP conenction before closing + it when the client is using the EDNS TCP keepalive + option. The default is 300 (30 seconds), the maximum + is 1200 (two minutes), and the minimum is 1 (one tenth + of a second). Values above the maximum or below the minimum + will be adjusted with a logged warning. + This value may be greater than + tcp-idle-timeout, because + clients using the EDNS TCP keepalive option are expected + to use TCP connections for more than one message. + This value can be updated at runtime by using + rndc tcp-timeouts. +
++ The timeout value (in units of 100 milliseconds) the + server will send in respones containing the EDNS TCP + keepalive option. This informs a client of the + amount of time it may keep the session open. + The default is 300 (30 seconds), the maximum is + 1200 (two minutes), and the minimum is 0, which + signals that the clients must close TCP connections + immediately. Ordinarily this should be set to the + same value as tcp-keepalive-timeout. + This value can be updated at runtime by using + rndc tcp-timeouts. +
++ This interval is effectively obsolete. Previously, + the server would remove expired resource records + from the cache every cleaning-interval minutes. + BIND 9 now manages cache + memory in a more sophisticated manner and does not + rely on the periodic cleaning any more. + Specifying this option therefore has no effect on + the server's behavior. +
++ The server will perform zone maintenance tasks + for all zones marked as dialup whenever this + interval expires. The default is 60 minutes. Reasonable + values are up + to 1 day (1440 minutes). The maximum value is 28 days + (40320 minutes). + If set to 0, no zone maintenance for these zones will occur. +
++ The server will scan the network interface list + every interface-interval + minutes. The default + is 60 minutes. The maximum value is 28 days (40320 minutes). + If set to 0, interface scanning will only occur when + the configuration file is loaded. After the scan, the + server will + begin listening for queries on any newly discovered + interfaces (provided they are allowed by the + listen-on configuration), and + will + stop listening on interfaces that have gone away. +
++ Name server statistics will be logged + every statistics-interval + minutes. The default is + 60. The maximum value is 28 days (40320 minutes). + If set to 0, no statistics will be logged. +
++ Not yet implemented in + BIND 9. +
++ All other things being equal, when the server chooses a name + server + to query from a list of name servers, it prefers the one that is + topologically closest to itself. The topology statement + takes an address_match_list and + interprets it + in a special way. Each top-level list element is assigned a + distance. + Non-negated elements get a distance based on their position in the + list, where the closer the match is to the start of the list, the + shorter the distance is between it and the server. A negated match + will be assigned the maximum distance from the server. If there + is no match, the address will get a distance which is further than + any non-negated list element, and closer than any negated element. + For example, +
+ +topology {
+ 10/8;
+ !1.2.3/24;
+ { 1.2/16; 3/8; };
+};
+
+ + will prefer servers on network 10 the most, followed by hosts + on network 1.2.0.0 (netmask 255.255.0.0) and network 3, with the + exception of hosts on network 1.2.3 (netmask 255.255.255.0), which + is preferred least of all. +
++ The default topology is +
+ + topology { localhost; localnets; };
+
+
+ + The topology option + is not implemented in BIND 9. +
++ The response to a DNS query may consist of multiple resource + records (RRs) forming a resource record set (RRset). + The name server will normally return the + RRs within the RRset in an indeterminate order + (but see the rrset-order + statement in the section called “RRset Ordering”). + The client resolver code should rearrange the RRs as appropriate, + that is, using any addresses on the local net in preference to + other addresses. + However, not all resolvers can do this or are correctly + configured. + When a client is using a local server, the sorting can be performed + in the server, based on the client's address. This only requires + configuring the name servers, not all the clients. +
+ ++ The sortlist statement (see below) + takes + an address_match_list and + interprets it even + more specifically than the topology + statement + does (the section called “Topology”). + Each top level statement in the sortlist must + itself be an explicit address_match_list with + one or two elements. The first element (which may be an IP + address, + an IP prefix, an ACL name or a nested address_match_list) + of each top level list is checked against the source address of + the query until a match is found. +
++ Once the source address of the query has been matched, if + the top level statement contains only one element, the actual + primitive + element that matched the source address is used to select the + address + in the response to move to the beginning of the response. If the + statement is a list of two elements, then the second element is + treated the same as the address_match_list in + a topology statement. Each top + level element + is assigned a distance and the address in the response with the + minimum + distance is moved to the beginning of the response. +
++ In the following example, any queries received from any of + the addresses of the host itself will get responses preferring + addresses + on any of the locally connected networks. Next most preferred are + addresses + on the 192.168.1/24 network, and after that either the + 192.168.2/24 + or + 192.168.3/24 network with no preference shown between these two + networks. Queries received from a host on the 192.168.1/24 network + will prefer other addresses on that network to the 192.168.2/24 + and + 192.168.3/24 networks. Queries received from a host on the + 192.168.4/24 + or the 192.168.5/24 network will only prefer other addresses on + their directly connected networks. +
+ +sortlist {
+ // IF the local host
+ // THEN first fit on the following nets
+ { localhost;
+ { localnets;
+ 192.168.1/24;
+ { 192.168.2/24; 192.168.3/24; }; }; };
+ // IF on class C 192.168.1 THEN use .1, or .2 or .3
+ { 192.168.1/24;
+ { 192.168.1/24;
+ { 192.168.2/24; 192.168.3/24; }; }; };
+ // IF on class C 192.168.2 THEN use .2, or .1 or .3
+ { 192.168.2/24;
+ { 192.168.2/24;
+ { 192.168.1/24; 192.168.3/24; }; }; };
+ // IF on class C 192.168.3 THEN use .3, or .1 or .2
+ { 192.168.3/24;
+ { 192.168.3/24;
+ { 192.168.1/24; 192.168.2/24; }; }; };
+ // IF .4 or .5 THEN prefer that net
+ { { 192.168.4/24; 192.168.5/24; };
+ };
+};
+
+ + The following example will give reasonable behavior for the + local host and hosts on directly connected networks. It is similar + to the behavior of the address sort in BIND 4.9.x. Responses sent + to queries from the local host will favor any of the directly + connected + networks. Responses sent to queries from any other hosts on a + directly + connected network will prefer addresses on that same network. + Responses + to other queries will not be sorted. +
+ +sortlist {
+ { localhost; localnets; };
+ { localnets; };
+};
+
+
+ + When multiple records are returned in an answer it may be + useful to configure the order of the records placed into the + response. The rrset-order statement permits + configuration of the ordering of the records in a + multiple-record response. + See also the sortlist statement, + the section called “The sortlist Statement”. +
++ An order_spec is defined as follows: +
+
+ [class class_name]
+ [type type_name]
+ [name "domain_name"]
+ order ordering
+
+ If no class is specified, the default is ANY. + If no type is specified, the default is ANY. + If no name is specified, the default is "*" (asterisk). +
++ The legal values for ordering are: +
+|
+ fixed + |
+
+ + Records are returned in the order they + are defined in the zone file. This option + is only available if BIND + is configured with "--enable-fixed-rrset" at + compile time. + + |
+
|
+ random + |
+
+ + Records are returned in some random order. + + |
+
|
+ cyclic + |
+
+ + Records are returned in a cyclic round-robin order, + rotating by one record per query. + ++ If BIND is configured with + "--enable-fixed-rrset" at compile time, then + the initial ordering of the RRset will match the + one specified in the zone file; otherwise the + initial ordering is indeterminate. + + |
+
|
+ none + |
+
+ + Records are returned in whatever order they were + retrieved from the database. This order is + indeterminate, but will be consistent as long as the + database is not modified. When no ordering is + specified, this is the default. + + |
+
+
++ For example: +
+rrset-order {
+ class IN type A name "host.example.com" order random;
+ order cyclic;
+};
+
+
+ will cause any responses for type A records in class IN that
+ have "host.example.com" as a
+ suffix, to always be returned
+ in random order. All other records are returned in cyclic order.
+
+ If multiple rrset-order statements + appear, they are not combined — the last one applies. +
++ By default, records are returned in indeterminate but + consistent order (see none above). +
+ ++ In this release of BIND 9, the + rrset-order statement does not support + "fixed" ordering by default. Fixed ordering can be enabled + at compile time by specifying "--enable-fixed-rrset" on + the "configure" command line. +
+
+ Sets the number of seconds to cache a
+ lame server indication. 0 disables caching. (This is
+ NOT recommended.)
+ The default is 600 (10 minutes) and the
+ maximum value is
+ 1800 (30 minutes).
+
+ Sets the number of seconds to cache a
+ SERVFAIL response due to DNSSEC validation failure or
+ other general server failure. If set to
+ 0, SERVFAIL caching is disabled.
+ The SERVFAIL cache is not consulted if a query has
+ the CD (Checking Disabled) bit set; this allows a
+ query that failed due to DNSSEC validation to be retried
+ without waiting for the SERVFAIL TTL to expire.
+
+ The maximum value is 30
+ seconds; any higher value will be silently
+ reduced. The default is 1
+ second.
+
+ To reduce network traffic and increase performance,
+ the server stores negative answers. max-ncache-ttl is
+ used to set a maximum retention time for these answers in
+ the server
+ in seconds. The default
+ max-ncache-ttl is 10800 seconds (3 hours).
+ max-ncache-ttl cannot exceed
+ 7 days and will
+ be silently truncated to 7 days if set to a greater value.
+
+ Sets the maximum time for which the server will + cache ordinary (positive) answers in seconds. + The default is 604800 (one week). + A value of zero may cause all queries to return + SERVFAIL, because of lost caches of intermediate + RRsets (such as NS and glue AAAA/A records) in the + resolution process. +
++ Sets the maximum time for which the server will + retain records past their normal expiry to + return them as stale records when the servers + for those records are not reachable. The default + is to not retain the record. +
++ rndc serve-stale can be used + to disable and re-enable the serving of stale + records at runtime. Reloading or reconfiguring + named will not re-enable serving + of stale records if they have been disabled via + rndc. +
+
+ The minimum number of root servers that
+ is required for a request for the root servers to be
+ accepted. The default
+ is 2.
+
+ Not implemented in BIND 9. +
+
+ Specifies the number of days into the future when
+ DNSSEC signatures automatically generated as a
+ result of dynamic updates (the section called “Dynamic Update”) will expire. There
+ is an optional second field which specifies how
+ long before expiry that the signatures will be
+ regenerated. If not specified, the signatures will
+ be regenerated at 1/4 of base interval. The second
+ field is specified in days if the base interval is
+ greater than 7 days otherwise it is specified in hours.
+ The default base interval is 30 days
+ giving a re-signing interval of 7 1/2 days. The maximum
+ values are 10 years (3660 days).
+
+ The signature inception time is unconditionally + set to one hour before the current time to allow + for a limited amount of clock skew. +
++ The sig-validity-interval + should be, at least, several multiples of the SOA + expire interval to allow for reasonable interaction + between the various timer and expiry dates. +
+
+ Specify the maximum number of nodes to be
+ examined in each quantum when signing a zone with
+ a new DNSKEY. The default is
+ 100.
+
+ Specify a threshold number of signatures that
+ will terminate processing a quantum when signing
+ a zone with a new DNSKEY. The default is
+ 10.
+
+ Specify a private RDATA type to be used when generating
+ signing state records. The default is
+ 65534.
+
+ It is expected that this parameter may be removed + in a future version once there is a standard type. +
+
+ Signing state records are used to internally by
+ named to track the current state of
+ a zone-signing process, i.e., whether it is still active
+ or has been completed. The records can be inspected
+ using the command
+ rndc signing -list zone.
+ Once named has finished signing
+ a zone with a particular key, the signing state
+ record associated with that key can be removed from
+ the zone by running
+ rndc signing -clear keyid/algorithm zone.
+ To clear all of the completed signing state
+ records for a zone, use
+ rndc signing -clear all zone.
+
+ These options control the server's behavior on refreshing a + zone + (querying for SOA changes) or retrying failed transfers. + Usually the SOA values for the zone are used, but these + values + are set by the master, giving slave server administrators + little + control over their contents. +
++ These options allow the administrator to set a minimum and + maximum refresh and retry time in seconds per-zone, + per-view, or globally. + These options are valid for slave and stub zones, + and clamp the SOA refresh and retry times to the specified + values. +
++ The following defaults apply. + min-refresh-time 300 seconds, + max-refresh-time 2419200 seconds + (4 weeks), min-retry-time 500 seconds, + and max-retry-time 1209600 seconds + (2 weeks). +
++ Sets the maximum advertised EDNS UDP buffer size in + bytes, to control the size of packets received from + authoritative servers in response to recursive queries. + Valid values are 512 to 4096 (values outside this range + will be silently adjusted to the nearest value within + it). The default value is 4096. +
++ The usual reason for setting + edns-udp-size to a non-default value + is to get UDP answers to pass through broken firewalls + that block fragmented packets and/or block UDP DNS + packets that are greater than 512 bytes. +
++ When named first queries a remote + server, it will advertise a UDP buffer size of 512, as + this has the greatest chance of success on the first try. +
++ If the initial response times out, named + will try again with plain DNS, and if that is successful, + it will be taken as evidence that the server does not + support EDNS. After enough failures using EDNS and + successes using plain DNS, named + will default to plain DNS for future communications + with that server. (Periodically, named + will send an EDNS query to see if the situation has + improved.) +
++ However, if the initial query is successful with + EDNS advertising a buffer size of 512, then + named will advertise progressively + larger buffer sizes on successive queries, until + responses begin timing out or + edns-udp-size is reached. +
++ The default buffer sizes used by named + are 512, 1232, 1432, and 4096, but never exceeding + edns-udp-size. (The values 1232 and + 1432 are chosen to allow for an IPv4/IPv6 encapsulated + UDP message to be sent without fragmentation at the + minimum MTU sizes for Ethernet and IPv6 networks.) +
++ Sets the maximum EDNS UDP message size + named will send in bytes. + Valid values are 512 to 4096 (values outside this + range will be silently adjusted to the nearest + value within it). The default value is 4096. +
++ This value applies to responses sent by a server; to + set the advertised buffer size in queries, see + edns-udp-size. +
++ The usual reason for setting + max-udp-size to a non-default + value is to get UDP answers to pass through broken + firewalls that block fragmented packets and/or + block UDP packets that are greater than 512 bytes. + This is independent of the advertised receive + buffer (edns-udp-size). +
++ Setting this to a low value will encourage additional + TCP traffic to the nameserver. +
+Specifies
+ the file format of zone files (see
+ the section called “Additional File Formats”).
+ The default value is text, which is the
+ standard textual representation, except for slave zones,
+ in which the default value is raw.
+ Files in other formats than text are
+ typically expected to be generated by the
+ named-compilezone tool, or dumped by
+ named.
+
+ Note that when a zone file in a different format than
+ text is loaded, named
+ may omit some of the checks which would be performed for a
+ file in the text format. In particular,
+ check-names checks do not apply
+ for the raw format. This means
+ a zone file in the raw format
+ must be generated with the same check level as that
+ specified in the named configuration
+ file. Also, map format files are
+ loaded directly into memory via memory mapping, with only
+ minimal checking.
+
+ This statement sets the + masterfile-format for all zones, + but can be overridden on a per-zone or per-view basis + by including a masterfile-format + statement within the zone or + view block in the configuration + file. +
+
+ Specifies the formatting of zone files during dump
+ when the masterfile-format is
+ text. (This option is ignored
+ with any other masterfile-format.)
+
+ When set to relative,
+ records are printed in a multi-line format with owner
+ names expressed relative to a shared origin. When set
+ to full, records are printed in
+ a single-line format with absolute owner names.
+ The full format is most suitable
+ when a zone file needs to be processed automatically
+ by a script. The relative format
+ is more human-readable, and is thus suitable when a
+ zone is to be edited by hand. The default is
+ relative.
+
+ Sets the maximum number of levels of recursion + that are permitted at any one time while servicing + a recursive query. Resolving a name may require + looking up a name server address, which in turn + requires resolving another name, etc; if the number + of indirections exceeds this value, the recursive + query is terminated and returns SERVFAIL. The + default is 7. +
++ Sets the maximum number of iterative queries that + may be sent while servicing a recursive query. + If more queries are sent, the recursive query + is terminated and returns SERVFAIL. Queries to + look up top level domains such as "com" and "net" + and the DNS root zone are exempt from this limitation. + The default is 75. +
++ The delay, in seconds, between sending sets of notify + messages for a zone. The default is five (5) seconds. +
++ The overall rate that NOTIFY messages are sent for all + zones is controlled by serial-query-rate. +
++ The maximum RSA exponent size, in bits, that will + be accepted when validating. Valid values are 35 + to 4096 bits. The default zero (0) is also accepted + and is equivalent to 4096. +
++ When a query is received for cached data which + is to expire shortly, named can + refresh the data from the authoritative server + immediately, ensuring that the cache always has an + answer available. +
+
+ The prefetch specifies the
+ "trigger" TTL value at which prefetch of the current
+ query will take place: when a cache record with a
+ lower TTL value is encountered during query processing,
+ it will be refreshed. Valid trigger TTL values are 1 to
+ 10 seconds. Values larger than 10 seconds will be silently
+ reduced to 10.
+ Setting a trigger TTL to zero (0) causes
+ prefetch to be disabled.
+ The default trigger TTL is 2.
+
+ An optional second argument specifies the "eligibility"
+ TTL: the smallest original
+ TTL value that will be accepted for a record to be
+ eligible for prefetching. The eligibility TTL must
+ be at least six seconds longer than the trigger TTL;
+ if it isn't, named will silently
+ adjust it upward.
+ The default eligibility TTL is 9.
+
+ When determining the next nameserver to try
+ preference IPv6 nameservers by this many milliseconds.
+ The default is 50 milliseconds.
+
+ The server provides some helpful diagnostic information
+ through a number of built-in zones under the
+ pseudo-top-level-domain bind in the
+ CHAOS class. These zones are part
+ of a
+ built-in view (see the section called “view Statement Grammar”) of
+ class
+ CHAOS which is separate from the
+ default view of class IN. Most global
+ configuration options (allow-query,
+ etc) will apply to this view, but some are locally
+ overridden: notify,
+ recursion and
+ allow-new-zones are
+ always set to no, and
+ rate-limit is set to allow
+ three responses per second.
+
+ If you need to disable these zones, use the options + below, or hide the built-in CHAOS + view by + defining an explicit view of class CHAOS + that matches all clients. +
+ +
+ The version the server should report
+ via a query of the name version.bind
+ with type TXT, class CHAOS.
+ The default is the real version number of this server.
+ Specifying version none
+ disables processing of the queries.
+
+ The hostname the server should report via a query of
+ the name hostname.bind
+ with type TXT, class CHAOS.
+ This defaults to the hostname of the machine hosting the
+ name server as
+ found by the gethostname() function. The primary purpose of such queries
+ is to
+ identify which of a group of anycast servers is actually
+ answering your queries. Specifying hostname none;
+ disables processing of the queries.
+
+ The ID the server should report when receiving a Name
+ Server Identifier (NSID) query, or a query of the name
+ ID.SERVER with type
+ TXT, class CHAOS.
+ The primary purpose of such queries is to
+ identify which of a group of anycast servers is actually
+ answering your queries. Specifying server-id none;
+ disables processing of the queries.
+ Specifying server-id hostname; will cause named to
+ use the hostname as found by the gethostname() function.
+ The default server-id is none.
+
+ The named server has some built-in + empty zones (SOA and NS records only). + These are for zones that should normally be answered locally + and which queries should not be sent to the Internet's root + servers. The official servers which cover these namespaces + return NXDOMAIN responses to these queries. In particular, + these cover the reverse namespaces for addresses from + RFC 1918, RFC 4193, RFC 5737 and RFC 6598. They also include the + reverse namespace for IPv6 local address (locally assigned), + IPv6 link local addresses, the IPv6 loopback address and the + IPv6 unknown address. +
++ The server will attempt to determine if a built-in zone + already exists or is active (covered by a forward-only + forwarding declaration) and will not create an empty + zone in that case. +
++ The current list of empty zones is: +
++
++ Empty zones are settable at the view level and only apply to + views of class IN. Disabled empty zones are only inherited + from options if there are no disabled empty zones specified + at the view level. To override the options list of disabled + zones, you can disable the root zone at the view level, for example: +
++ disable-empty-zone "."; ++
+
++ If you are using the address ranges covered here, you should + already have reverse zones covering the addresses you use. + In practice this appears to not be the case with many queries + being made to the infrastructure servers for names in these + spaces. So many in fact that sacrificial servers were needed + to be deployed to channel the query load away from the + infrastructure servers. +
++ The real parent servers for these zones should disable all + empty zone under the parent zone they serve. For the real + root servers, this is all built-in empty zones. This will + enable them to return referrals to deeper in the tree. +
++ Specify what server name will appear in the returned + SOA record for empty zones. If none is specified, then + the zone's name will be used. +
++ Specify what contact name will appear in the returned + SOA record for empty zones. If none is specified, then + "." will be used. +
++ Enable or disable all empty zones. By default, they + are enabled. +
++ Disable individual empty zones. By default, none are + disabled. This option can be specified multiple times. +
+
+ BIND 9 provides the ability to filter
+ out DNS responses from external DNS servers containing
+ certain types of data in the answer section.
+ Specifically, it can reject address (A or AAAA) records if
+ the corresponding IPv4 or IPv6 addresses match the given
+ address_match_list of the
+ deny-answer-addresses option.
+ It can also reject CNAME or DNAME records if the "alias"
+ name (i.e., the CNAME alias or the substituted query name
+ due to DNAME) matches the
+ given namelist of the
+ deny-answer-aliases option, where
+ "match" means the alias name is a subdomain of one of
+ the name_list elements.
+ If the optional namelist is specified
+ with except-from, records whose query name
+ matches the list will be accepted regardless of the filter
+ setting.
+ Likewise, if the alias name is a subdomain of the
+ corresponding zone, the deny-answer-aliases
+ filter will not apply;
+ for example, even if "example.com" is specified for
+ deny-answer-aliases,
+
www.example.com. CNAME xxx.example.com.+ +
+ returned by an "example.com" server will be accepted. +
+ +
+ In the address_match_list of the
+ deny-answer-addresses option, only
+ ip_addr
+ and ip_prefix
+ are meaningful;
+ any key_id will be silently ignored.
+
+ If a response message is rejected due to the filtering, + the entire message is discarded without being cached, and + a SERVFAIL error will be returned to the client. +
+ ++ This filtering is intended to prevent "DNS rebinding attacks," in + which an attacker, in response to a query for a domain name the + attacker controls, returns an IP address within your own network or + an alias name within your own domain. + A naive web browser or script could then serve as an + unintended proxy, allowing the attacker + to get access to an internal node of your local network + that couldn't be externally accessed otherwise. + See the paper available at + + http://portal.acm.org/citation.cfm?id=1315245.1315298 + + for more details about the attacks. +
+ ++ For example, if you own a domain named "example.net" and + your internal network uses an IPv4 prefix 192.0.2.0/24, + you might specify the following rules: +
+ +deny-answer-addresses { 192.0.2.0/24; } except-from { "example.net"; };
+deny-answer-aliases { "example.net"; };
+
+
+ + If an external attacker lets a web browser in your local + network look up an IPv4 address of "attacker.example.com", + the attacker's DNS server would return a response like this: +
+ +attacker.example.com. A 192.0.2.1+ +
+ in the answer section. + Since the rdata of this record (the IPv4 address) matches + the specified prefix 192.0.2.0/24, this response will be + ignored. +
+ ++ On the other hand, if the browser looks up a legitimate + internal web server "www.example.net" and the + following response is returned to + the BIND 9 server +
+ +www.example.net. A 192.0.2.2+ +
+ it will be accepted since the owner name "www.example.net" + matches the except-from element, + "example.net". +
+ ++ Note that this is not really an attack on the DNS per se. + In fact, there is nothing wrong for an "external" name to + be mapped to your "internal" IP address or domain name + from the DNS point of view. + It might actually be provided for a legitimate purpose, + such as for debugging. + As long as the mapping is provided by the correct owner, + it is not possible or does not make sense to detect + whether the intent of the mapping is legitimate or not + within the DNS. + The "rebinding" attack must primarily be protected at the + application that uses the DNS. + For a large site, however, it may be difficult to protect + all possible applications at once. + This filtering feature is provided only to help such an + operational environment; + it is generally discouraged to turn it on unless you are + very sure you have no other choice and the attack is a + real threat for your applications. +
+ ++ Care should be particularly taken if you want to use this + option for addresses within 127.0.0.0/8. + These addresses are obviously "internal", but many + applications conventionally rely on a DNS mapping from + some name to such an address. + Filtering out DNS records containing this address + spuriously can break such applications. +
++ BIND 9 includes a limited + mechanism to modify DNS responses for requests + analogous to email anti-spam DNS blacklists. + Responses can be changed to deny the existence of domains (NXDOMAIN), + deny the existence of IP addresses for domains (NODATA), + or contain other IP addresses or data. +
+ ++ Response policy zones are named in the + response-policy option for the view or among the + global options if there is no response-policy option for the view. + Response policy zones are ordinary DNS zones containing RRsets + that can be queried normally if allowed. + It is usually best to restrict those queries with something like + allow-query { localhost; };. + Note that zones using masterfile-format map + cannot be used as policy zones. +
+ ++ A response-policy option can support + multiple policy zones. To maximize performance, a radix + tree is used to quickly identify response policy zones + containing triggers that match the current query. This + imposes an upper limit of 32 on the number of policy zones + in a single response-policy option; more + than that is a configuration error. +
+ ++ Five policy triggers can be encoded in RPZ records. +
+
+ IP records are triggered by the IP address of the
+ DNS client.
+ Client IP address triggers are encoded in records that have
+ owner names that are subdomains of
+ rpz-client-ip relativized to the
+ policy zone origin name
+ and encode an address or address block.
+ IPv4 addresses are represented as
+ prefixlength.B4.B3.B2.B1.rpz-client-ip.
+ The IPv4 prefix length must be between 1 and 32.
+ All four bytes, B4, B3, B2, and B1, must be present.
+ B4 is the decimal value of the least significant byte of the
+ IPv4 address as in IN-ADDR.ARPA.
+
+ IPv6 addresses are encoded in a format similar
+ to the standard IPv6 text representation,
+ prefixlength.W8.W7.W6.W5.W4.W3.W2.W1.rpz-client-ip.
+ Each of W8,...,W1 is a one to four digit hexadecimal number
+ representing 16 bits of the IPv6 address as in the standard
+ text representation of IPv6 addresses, but reversed as in
+ IP6.ARPA. (Note that this representation of IPv6
+ address is different from IP6.ARPA where each hex
+ digit occupies a label.)
+ All 8 words must be present except when one set of consecutive
+ zero words is replaced with .zz.
+ analogous to double colons (::) in standard IPv6 text
+ encodings.
+ The IPv6 prefix length must be between 1 and 128.
+
+ QNAME policy records are triggered by query names of + requests and targets of CNAME records resolved to generate + the response. + The owner name of a QNAME policy record is + the query name relativized to the policy zone. +
++ IP triggers are IP addresses in an + A or AAAA record in the ANSWER section of a response. + They are encoded like client-IP triggers except as + subdomains of rpz-ip. +
++ NSDNAME triggers match names of authoritative servers + for the query name, a parent of the query name, a CNAME for + query name, or a parent of a CNAME. + They are encoded as subdomains of + rpz-nsdname relativized + to the RPZ origin name. + NSIP triggers match IP addresses in A and + AAAA RRsets for domains that can be checked against NSDNAME + policy records. + The nsdname-enable phrase turns NSDNAME + triggers off or on for a single policy zone or all + zones. +
++ NSIP triggers match the IP addresses of authoritative + servers. They are enncoded like IP triggers, except as + subdomains of rpz-nsip. + NSDNAME and NSIP triggers are checked only for names with at + least min-ns-dots dots. + The default value of min-ns-dots is + 1, to exclude top level domains. + The nsip-enable phrase turns NSIP + triggers off or on for a single policy zone or all + zones. +
+
+ If a name server's IP address is not yet known,
+ named will recursively look up
+ the IP address before applying an RPZ-NSIP rule.
+ This can cause a processing delay. To speed up
+ processing at the cost of precision, the
+ nsip-wait-recurse option
+ can be used: when set to no,
+ RPZ-NSIP rules will only be applied when a name
+ servers's IP address has already been looked up and
+ cached. If a server's IP address is not in the
+ cache, then the RPZ-NSIP rule will be ignored,
+ but the address will be looked up in the
+ background, and the rule will be applied
+ to subsequent queries. The default is
+ yes, meaning RPZ-NSIP
+ rules should always be applied even if an
+ address needs to be looked up first.
+
+
+ ++ The query response is checked against all response policy zones, + so two or more policy records can be triggered by a response. + Because DNS responses are rewritten according to at most one + policy record, a single record encoding an action (other than + DISABLED actions) must be chosen. + Triggers or the records that encode them are chosen for the + rewriting in the following order: +
++
+ ++ When the processing of a response is restarted to resolve + DNAME or CNAME records and a policy record set has + not been triggered, + all response policy zones are again consulted for the + DNAME or CNAME names and addresses. +
+ ++ RPZ record sets are any types of DNS record except + DNAME or DNSSEC that encode actions or responses to + individual queries. + Any of the policies can be used with any of the triggers. + For example, while the TCP-only policy is + commonly used with client-IP triggers, + it can be used with any type of trigger to force the use of + TCP for responses with owner names in a zone. +
++ The whitelist policy is specified + by a CNAME whose target is rpz-passthru. + It causes the response to not be rewritten + and is most often used to "poke holes" in policies for + CIDR blocks. +
++ The blacklist policy is specified + by a CNAME whose target is rpz-drop. + It causes the response to be discarded. + Nothing is sent to the DNS client. +
++ The "slip" policy is specified + by a CNAME whose target is rpz-tcp-only. + It changes UDP responses to short, truncated DNS responses + that require the DNS client to try again with TCP. + It is used to mitigate distributed DNS reflection attacks. +
++ The domain undefined response is encoded + by a CNAME whose target is the root domain (.) +
++ The empty set of resource records is specified by + CNAME whose target is the wildcard top-level + domain (*.). + It rewrites the response to NODATA or ANCOUNT=1. +
++ A set of ordinary DNS records can be used to answer queries. + Queries for record types not the set are answered with + NODATA. +
+ ++ A special form of local data is a CNAME whose target is a + wildcard such as *.example.com. + It is used as if were an ordinary CNAME after the asterisk (*) + has been replaced with the query name. + The purpose for this special form is query logging in the + walled garden's authority DNS server. +
++
+ ++ All of the actions specified in all of the individual records + in a policy zone + can be overridden with a policy clause in the + response-policy option. + An organization using a policy zone provided by another + organization might use this mechanism to redirect domains + to its own walled garden. +
+The placeholder policy says "do not override but + perform the action specified in the zone." +
++ The testing override policy causes policy zone records to do + nothing but log what they would have done if the + policy zone were not disabled. + The response to the DNS query will be written (or not) + according to any triggered policy records that are not + disabled. + Disabled policy zones should appear first, + because they will often not be logged + if a higher precedence trigger is found first. +
++ override with the corresponding per-record policy. +
++ causes all RPZ policy records to act as if they were + "cname domain" records. +
++
+ ++ By default, the actions encoded in a response policy zone + are applied only to queries that ask for recursion (RD=1). + That default can be changed for a single policy zone or + all response policy zones in a view + with a recursive-only no clause. + This feature is useful for serving the same zone files + both inside and outside an RFC 1918 cloud and using RPZ to + delete answers that would otherwise contain RFC 1918 values + on the externally visible name server or view. +
+ ++ Also by default, RPZ actions are applied only to DNS requests + that either do not request DNSSEC metadata (DO=0) or when no + DNSSEC records are available for request name in the original + zone (not the response policy zone). This default can be + changed for all response policy zones in a view with a + break-dnssec yes clause. In that case, RPZ + actions are applied regardless of DNSSEC. The name of the + clause option reflects the fact that results rewritten by RPZ + actions cannot verify. +
+ ++ No DNS records are needed for a QNAME or Client-IP trigger. + The name or IP address itself is sufficient, + so in principle the query name need not be recursively resolved. + However, not resolving the requested + name can leak the fact that response policy rewriting is in use + and that the name is listed in a policy zone to operators of + servers for listed names. To prevent that information leak, by + default any recursion needed for a request is done before any + policy triggers are considered. Because listed domains often + have slow authoritative servers, this behavior can cost + significant time. + The qname-wait-recurse yes option + overrides the default and enables that behavior + when recursion cannot change a non-error response. + The option does not affect QNAME or client-IP triggers + in policy zones listed + after other zones containing IP, NSIP and NSDNAME triggers, because + those may depend on the A, AAAA, and NS records that would be + found during recursive resolution. It also does not affect + DNSSEC requests (DO=1) unless break-dnssec yes + is in use, because the response would depend on whether or not + RRSIG records were found during resolution. + Using this option can cause error responses such as SERVFAIL to + appear to be rewritten, since no recursion is being done to + discover problems at the authoritative server. +
+ ++ The dnsrps-enable yes option turns on + the DNS Rsponse Policy Service (DNSRPS) interface, if it has been + compiled in to named using + configure --enable-dnsrps. +
+ ++ The dnsrps-options block provides additional + RPZ configuration settings, which are passed through to the + DNSRPS provider library. + Multiple DNSRPS settings in an dnsrps-options + string should be separated with semi-colons. + The DNSRPS provider, librpz, is passed a configuration string + consisting of the dnsrps-options text, + concatenated with settings derived from the + response-policy statement. +
+ ++ Note: The dnsrps-options text should only include + configuration settings that are specific to the DNSRPS + provider. For example, the DNSRPS provider from + Farsight Security takes options such as + dnsrpzd-conf, + dnsrpzd-sock, and + dnzrpzd-args (for details of these options, + see the librpz documentation). + Other RPZ configuration settings could be included in + dnsrps-options + as well, but if named were switched + back to traditional RPZ by setting + dnsrps-enable to "no", those options would + be ignored. +
+ ++ The TTL of a record modified by RPZ policies is set from the + TTL of the relevant record in policy zone. It is then limited + to a maximum value. + The max-policy-ttl clause changes the + maximum seconds from its default of 5. +
+ ++ For example, you might use this option statement +
+ response-policy { zone "badlist"; };
+ + and this zone statement +
+ zone "badlist" {type master; file "master/badlist"; allow-query {none;}; };
+ + with this zone file +
+$TTL 1H +@ SOA LOCALHOST. named-mgr.example.com (1 1h 15m 30d 2h) + NS LOCALHOST. + +; QNAME policy records. There are no periods (.) after the owner names. +nxdomain.domain.com CNAME . ; NXDOMAIN policy +*.nxdomain.domain.com CNAME . ; NXDOMAIN policy +nodata.domain.com CNAME *. ; NODATA policy +*.nodata.domain.com CNAME *. ; NODATA policy +bad.domain.com A 10.0.0.1 ; redirect to a walled garden + AAAA 2001:2::1 +bzone.domain.com CNAME garden.example.com. + +; do not rewrite (PASSTHRU) OK.DOMAIN.COM +ok.domain.com CNAME rpz-passthru. + +; redirect x.bzone.domain.com to x.bzone.domain.com.garden.example.com +*.bzone.domain.com CNAME *.garden.example.com. + + +; IP policy records that rewrite all responses containing A records in 127/8 +; except 127.0.0.1 +8.0.0.0.127.rpz-ip CNAME . +32.1.0.0.127.rpz-ip CNAME rpz-passthru. + +; NSDNAME and NSIP policy records +ns.domain.com.rpz-nsdname CNAME . +48.zz.2.2001.rpz-nsip CNAME . + +; blacklist and whitelist some DNS clients +112.zz.2001.rpz-client-ip CNAME rpz-drop. +8.0.0.0.127.rpz-client-ip CNAME rpz-drop. + +; force some DNS clients and responses in the example.com zone to TCP +16.0.0.1.10.rpz-client-ip CNAME rpz-tcp-only. +example.com CNAME rpz-tcp-only. +*.example.com CNAME rpz-tcp-only. + ++
+ RPZ can affect server performance. + Each configured response policy zone requires the server to + perform one to four additional database lookups before a + query can be answered. + For example, a DNS server with four policy zones, each with all + four kinds of response triggers, QNAME, IP, NSIP, and + NSDNAME, requires a total of 17 times as many database + lookups as a similar DNS server with no response policy zones. + A BIND9 server with adequate memory and one + response policy zone with QNAME and IP triggers might achieve a + maximum queries-per-second rate about 20% lower. + A server with four response policy zones with QNAME and IP + triggers might have a maximum QPS rate about 50% lower. +
+ ++ Responses rewritten by RPZ are counted in the + RPZRewrites statistics. +
+ ++ The log clause can be used to optionally + turn off rewrite logging for a particular response policy + zone. By default, all rewrites are logged. +
+ +
+ Updates to RPZ zones are processed asynchronously; if there
+ is more than one update pending they are bundled together.
+ If an update to a RPZ zone (for example, via IXFR) happens less
+ than min-update-interval seconds after the most
+ recent update, then the changes will not be carried out until this
+ interval has elapsed. The default is 5 seconds.
+
+ Excessive almost identical UDP responses + can be controlled by configuring a + rate-limit clause in an + options or view statement. + This mechanism keeps authoritative BIND 9 from being used + in amplifying reflection denial of service (DoS) attacks. + Short truncated (TC=1) responses can be sent to provide + rate-limited responses to legitimate clients within + a range of forged, attacked IP addresses. + Legitimate clients react to dropped or truncated response + by retrying with UDP or with TCP respectively. +
+ ++ This mechanism is intended for authoritative DNS servers. + It can be used on recursive servers but can slow + applications such as SMTP servers (mail receivers) and + HTTP clients (web browsers) that repeatedly request the + same domains. + When possible, closing "open" recursive servers is better. +
+ ++ Response rate limiting uses a "credit" or "token bucket" scheme. + Each combination of identical response and client + has a conceptual account that earns a specified number + of credits every second. + A prospective response debits its account by one. + Responses are dropped or truncated + while the account is negative. + Responses are tracked within a rolling window of time + which defaults to 15 seconds, but can be configured with + the window option to any value from + 1 to 3600 seconds (1 hour). + The account cannot become more positive than + the per-second limit + or more negative than window + times the per-second limit. + When the specified number of credits for a class of + responses is set to 0, those responses are not rate limited. +
+ ++ The notions of "identical response" and "DNS client" + for rate limiting are not simplistic. + All responses to an address block are counted as if to a + single client. + The prefix lengths of addresses blocks are + specified with ipv4-prefix-length (default 24) + and ipv6-prefix-length (default 56). +
+ ++ All non-empty responses for a valid domain name (qname) + and record type (qtype) are identical and have a limit specified + with responses-per-second + (default 0 or no limit). + All empty (NODATA) responses for a valid domain, + regardless of query type, are identical. + Responses in the NODATA class are limited by + nodata-per-second + (default responses-per-second). + Requests for any and all undefined subdomains of a given + valid domain result in NXDOMAIN errors, and are identical + regardless of query type. + They are limited by nxdomains-per-second + (default responses-per-second). + This controls some attacks using random names, but + can be relaxed or turned off (set to 0) + on servers that expect many legitimate + NXDOMAIN responses, such as from anti-spam blacklists. + Referrals or delegations to the server of a given + domain are identical and are limited by + referrals-per-second + (default responses-per-second). +
+ ++ Responses generated from local wildcards are counted and limited + as if they were for the parent domain name. + This controls flooding using random.wild.example.com. +
+ ++ All requests that result in DNS errors other + than NXDOMAIN, such as SERVFAIL and FORMERR, are identical + regardless of requested name (qname) or record type (qtype). + This controls attacks using invalid requests or distant, + broken authoritative servers. + By default the limit on errors is the same as the + responses-per-second value, + but it can be set separately with + errors-per-second. +
+ ++ Many attacks using DNS involve UDP requests with forged source + addresses. + Rate limiting prevents the use of BIND 9 to flood a network + with responses to requests with forged source addresses, + but could let a third party block responses to legitimate requests. + There is a mechanism that can answer some legitimate + requests from a client whose address is being forged in a flood. + Setting slip to 2 (its default) causes every + other UDP request to be answered with a small truncated (TC=1) + response. + The small size and reduced frequency, and so lack of + amplification, of "slipped" responses make them unattractive + for reflection DoS attacks. + slip must be between 0 and 10. + A value of 0 does not "slip": + no truncated responses are sent due to rate limiting, + all responses are dropped. + A value of 1 causes every response to slip; + values between 2 and 10 cause every n'th response to slip. + Some error responses including REFUSED and SERVFAIL + cannot be replaced with truncated responses and are instead + leaked at the slip rate. +
+ ++ (NOTE: Dropped responses from an authoritative server may + reduce the difficulty of a third party successfully forging + a response to a recursive resolver. The best security + against forged responses is for authoritative operators + to sign their zones using DNSSEC and for resolver operators + to validate the responses. When this is not an option, + operators who are more concerned with response integrity + than with flood mitigation may consider setting + slip to 1, causing all rate-limited + responses to be truncated rather than dropped. This reduces + the effectiveness of rate-limiting against reflection attacks.) +
+ ++ When the approximate query per second rate exceeds + the qps-scale value, + then the responses-per-second, + errors-per-second, + nxdomains-per-second and + all-per-second values are reduced by the + ratio of the current rate to the qps-scale value. + This feature can tighten defenses during attacks. + For example, with + qps-scale 250; responses-per-second 20; and + a total query rate of 1000 queries/second for all queries from + all DNS clients including via TCP, + then the effective responses/second limit changes to + (250/1000)*20 or 5. + Responses sent via TCP are not limited + but are counted to compute the query per second rate. +
+ ++ The optional domain clause specifies + the namespace to which rate limits will apply. It + is possible to use different rate limits for different names + by specifying multiple rate-limit blocks + with different domain clauses. + The rate-limit statement's + domain most closely matches the query + name will be the one applied to a given query. +
+ ++ Rate limiters for different name spaces maintain + separate counters: If, for example, there is a + rate-limit statement for "com" and + another for "example.com", queries matching "example.com" + will not be debited against the rate limiter for "com". +
+ ++ If a rate-limit statement does not specify a + domain, then it applies to the root domain + (".") and thus affects the entire DNS namespace, except those + portions covered by other rate-limit + statements. +
+ ++ Communities of DNS clients can be given their own parameters or no + rate limiting by putting + rate-limit statements in view + statements instead of the global option + statement. + A rate-limit statement in a view replaces, + rather than supplementing, a rate-limit + statement among the main options. + DNS clients within a view can be exempted from rate limits + with the exempt-clients clause. +
+ ++ UDP responses of all kinds can be limited with the + all-per-second phrase. This rate + limiting is unlike the rate limiting provided by + responses-per-second, + errors-per-second, and + nxdomains-per-second on a DNS server + which are often invisible to the victim of a DNS + reflection attack. Unless the forged requests of the + attack are the same as the legitimate requests of the + victim, the victim's requests are not affected. Responses + affected by an all-per-second limit + are always dropped; the slip value + has no effect. An all-per-second + limit should be at least 4 times as large as the other + limits, because single DNS clients often send bursts + of legitimate requests. For example, the receipt of a + single mail message can prompt requests from an SMTP + server for NS, PTR, A, and AAAA records as the incoming + SMTP/TCP/IP connection is considered. The SMTP server + can need additional NS, A, AAAA, MX, TXT, and SPF records + as it considers the STMP Mail From + command. Web browsers often repeatedly resolve the + same names that are repeated in HTML <IMG> tags + in a page. all-per-second is similar + to the rate limiting offered by firewalls but often + inferior. Attacks that justify ignoring the contents + of DNS responses are likely to be attacks on the DNS + server itself. They usually should be discarded before + the DNS server spends resources make TCP connections + or parsing DNS requests, but that rate limiting must + be done before the DNS server sees the requests. +
+ ++ The maximum size of the table used to track requests and + rate limit responses is set with max-table-size. + Each entry in the table is between 40 and 80 bytes. + The table needs approximately as many entries as the number + of requests received per second. + The default is 20,000. + To reduce the cold start of growing the table, + min-table-size (default 500) + can set the minimum table size. + Enable rate-limit category logging to monitor + expansions of the table and inform + choices for the initial and maximum table size. +
+ ++ Use log-only yes to test rate limiting parameters + without actually dropping any requests. +
+ ++ Responses dropped by rate limits are included in the + RateDropped and QryDropped + statistics. + Responses that truncated by rate limits are included in + RateSlipped and RespTruncated. +
++ Named supports NXDOMAIN redirection via two methods: +
++
++ With both methods when named gets a NXDOMAIN response + it examines a separate namespace to see if the NXDOMAIN + response should be replaced with an alternative response. +
++ With a redirect zone (zone "." { type redirect; };), the + data used to replace the NXDOMAIN is held in a single + zone which is not part of the normal namespace. All the + redirect information is contained in the zone; there are + no delegations. +
++ With a redirect namespace (option { nxdomain-redirect + <suffix> };) the data used to replace the + NXDOMAIN is part of the normal namespace and is looked up by + appending the specified suffix to the original query name. + This roughly doubles the cache required to process NXDOMAIN + responses as you have the original NXDOMAIN response and + the replacement data or a NXDOMAIN indicating that there + is no replacement. +
++ If both a redirect zone and a redirect namespace are configured, + the redirect zone is tried first. +
+server (+ +ip_addr|ip_prefix) { + [ bogusyes_or_no; ] + [ provide-ixfryes_or_no; ] + [ request-ixfryes_or_no; ] + [ request-expireyes_or_no; ] + [ request-nsidyes_or_no; ] + [ send-cookieyes_or_no; ] + [ ednsyes_or_no; ] + [ edns-udp-sizenumber; ] + [ edns-versionnumber; ] + [ max-udp-sizenumber; ] + [ paddingnumber; ] + [ tcp-onlyyes_or_no; ] + [ tcp-keepaliveyes_or_no; ] + [ transfersnumber; ] + [ transfer-format ( one-answer | many-answers ) ; ] + [ keys {key_id} ; ] + [ transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ notify-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ notify-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ query-source ( [ address ] (ip_addr|*) ) + [ port (ip_port|*) ] [ dscpip_dscp] ; ] + [ query-source-v6 ( [ address ] (ip_addr|*) ) + [ port (ip_port|*) ] [ dscpip_dscp] ; ] + [ use-queryport-poolyes_or_no; ] + [ queryport-pool-portsnumber; ] + [ queryport-pool-updateintervalnumber; ] +} ; +
+ The server statement defines
+ characteristics
+ to be associated with a remote name server. If a prefix length is
+ specified, then a range of servers is covered. Only the most
+ specific
+ server clause applies regardless of the order in
+ named.conf.
+
+ The server statement can occur at + the top level of the + configuration file or inside a view + statement. + If a view statement contains + one or more server statements, only + those + apply to the view and any top-level ones are ignored. + If a view contains no server + statements, + any top-level server statements are + used as + defaults. +
+ ++ If you discover that a remote server is giving out bad data, + marking it as bogus will prevent further queries to it. The + default + value of bogus is no. +
++ The provide-ixfr clause determines + whether + the local server, acting as master, will respond with an + incremental + zone transfer when the given remote server, a slave, requests it. + If set to yes, incremental transfer + will be provided + whenever possible. If set to no, + all transfers + to the remote server will be non-incremental. If not set, the + value + of the provide-ixfr option in the + view or + global options block is used as a default. +
+ ++ The request-ixfr clause determines + whether + the local server, acting as a slave, will request incremental zone + transfers from the given remote server, a master. If not set, the + value of the request-ixfr option in + the view or global options block is used as a default. It may + also be set in the zone block and, if set there, it will + override the global or view setting for that zone. +
+ ++ IXFR requests to servers that do not support IXFR will + automatically + fall back to AXFR. Therefore, there is no need to manually list + which servers support IXFR and which ones do not; the global + default + of yes should always work. + The purpose of the provide-ixfr and + request-ixfr clauses is + to make it possible to disable the use of IXFR even when both + master + and slave claim to support it, for example if one of the servers + is buggy and crashes or corrupts data when IXFR is used. +
+ ++ The request-expire clause determines + whether the local server, when acting as a slave, will + request the EDNS EXPIRE value. The EDNS EXPIRE value + indicates the remaining time before the zone data will + expire and need to be be refreshed. This is used + when a secondary server transfers a zone from another + secondary server; when transferring from the primary, the + expiration timer is set from the EXPIRE field of the SOA + record instead. + The default is yes. +
+ ++ The edns clause determines whether + the local server will attempt to use EDNS when communicating + with the remote server. The default is yes. +
+ ++ The edns-udp-size option sets the + EDNS UDP size that is advertised by named + when querying the remote server. Valid values are 512 + to 4096 bytes (values outside this range will be silently + adjusted to the nearest value within it). This option + is useful when you wish to advertise a different value + to this server than the value you advertise globally, + for example, when there is a firewall at the remote + site that is blocking large replies. (Note: Currently, + this sets a single UDP size for all packets sent to the + server; named will not deviate from + this value. This differs from the behavior of + edns-udp-size in options + or view statements, where it specifies + a maximum value. The server statement + behavior may be brought into conformance with the + options/view behavior in future releases.) +
+ ++ The edns-version option sets the + maximum EDNS VERSION that will be sent to the server(s) + by the resolver. The actual EDNS version sent is still + subject to normal EDNS version negotiation rules (see + RFC 6891), the maximum EDNS version supported by the + server, and any other heuristics that indicate that a + lower version should be sent. This option is intended + to be used when a remote server reacts badly to a given + EDNS version or higher; it should be set to the highest + version the remote server is known to support. Valid + values are 0 to 255; higher values will be silently + adjusted. This option will not be needed until higher + EDNS versions than 0 are in use. +
+ ++ The max-udp-size option sets the + maximum EDNS UDP message size named + will send. Valid values are 512 to 4096 bytes (values + outside this range will be silently adjusted). This + option is useful when you know that there is a firewall + that is blocking large replies from named. +
+ ++ The padding option adds EDNS Padding + options to outgoing messages, increasing the packet size to + a multiple of the specified block size. Valid block sizes + range from 0 (the default, which disables the use of + EDNS Padding) to 512 bytes. Larger values will be reduced + to 512, with a logged warning. + Note: This option is not currently compatible with no TSIG + or SIG(0), as the EDNS OPT record containing the padding + would have to be added to the packet after it had already + been signed. +
+ ++ The tcp-only option sets the transport + protocol to TCP. The default is to use the UDP transport + and to fallback on TCP only when a truncated response + is received. +
+ ++ The tcp-keepalive option adds EDNS + TCP keepalive to messages sent over TCP. Note currently + idle timeouts in responses are ignored. +
+ ++ The server supports two zone transfer methods. The first, one-answer, + uses one DNS message per resource record transferred. many-answers packs + as many resource records as possible into a message. many-answers is + more efficient, but is only known to be understood by BIND 9, BIND + 8.x, and patched versions of BIND + 4.9.5. You can specify which method + to use for a server with the transfer-format option. + If transfer-format is not + specified, the transfer-format + specified + by the options statement will be + used. +
+ +transfers + is used to limit the number of concurrent inbound zone + transfers from the specified server. If no + transfers clause is specified, the + limit is set according to the + transfers-per-ns option. +
+ ++ The keys clause identifies a + key_id defined by the key statement, + to be used for transaction security (TSIG, the section called “TSIG”) + when talking to the remote server. + When a request is sent to the remote server, a request signature + will be generated using the key specified here and appended to the + message. A request originating from the remote server is not + required + to be signed by this key. +
+ ++ Only a single key per server is currently supported. +
+ ++ The transfer-source and + transfer-source-v6 clauses specify + the IPv4 and IPv6 source + address to be used for zone transfer with the remote server, + respectively. + For an IPv4 remote server, only transfer-source can + be specified. + Similarly, for an IPv6 remote server, only + transfer-source-v6 can be + specified. + For more details, see the description of + transfer-source and + transfer-source-v6 in + the section called “Zone Transfers”. +
+ ++ The notify-source and + notify-source-v6 clauses specify the + IPv4 and IPv6 source address to be used for notify + messages sent to remote servers, respectively. For an + IPv4 remote server, only notify-source + can be specified. Similarly, for an IPv6 remote server, + only notify-source-v6 can be specified. +
+ ++ The query-source and + query-source-v6 clauses specify the + IPv4 and IPv6 source address to be used for queries + sent to remote servers, respectively. For an IPv4 + remote server, only query-source can + be specified. Similarly, for an IPv6 remote server, + only query-source-v6 can be specified. +
+ ++ The request-nsid clause determines + whether the local server will add a NSID EDNS option + to requests sent to the server. This overrides + request-nsid set at the view or + option level. +
+ ++ The send-cookie clause determines + whether the local server will add a COOKIE EDNS option + to requests sent to the server. This overrides + send-cookie set at the view or + option level. The named server may + determine that COOKIE is not supported by the remote server + and not add a COOKIE EDNS option to requests. +
+statistics-channels { + [ inet (+ip_addr|*) [ portip_port] + [ allow {address_match_list} ] ; ] + ... +}; +
+ The statistics-channels statement + declares communication channels to be used by system + administrators to get access to statistics information of + the name server. +
+ ++ This statement intends to be flexible to support multiple + communication protocols in the future, but currently only + HTTP access is supported. + It requires that BIND 9 be compiled with libxml2 and/or + json-c (also known as libjson0); the + statistics-channels statement is + still accepted even if it is built without the library, + but any HTTP access will fail with an error. +
+ +
+ An inet control channel is a TCP socket
+ listening at the specified ip_port on the
+ specified ip_addr, which can be an IPv4 or IPv6
+ address. An ip_addr of *
+ (asterisk) is
+ interpreted as the IPv4 wildcard address; connections will be
+ accepted on any of the system's IPv4 addresses.
+ To listen on the IPv6 wildcard address,
+ use an ip_addr of ::.
+
+ If no port is specified, port 80 is used for HTTP channels.
+ The asterisk "*" cannot be used for
+ ip_port.
+
+ The attempt of opening a statistics channel is + restricted by the optional allow clause. + Connections to the statistics channel are permitted based on the + address_match_list. + If no allow clause is present, + named accepts connection + attempts from any address; since the statistics may + contain sensitive internal information, it is highly + recommended to restrict the source of connection requests + appropriately. +
+ ++ If no statistics-channels statement is present, + named will not open any communication channels. +
+ ++ The statistics are available in various formats and views + depending on the URI used to access them. For example, if + the statistics channel is configured to listen on 127.0.0.1 + port 8888, then the statistics are accessible in XML format at + http://127.0.0.1:8888/ or + http://127.0.0.1:8888/xml. A CSS file is + included which can format the XML statistics into tables + when viewed with a stylesheet-capable browser, and into + charts and graphs using the Google Charts API when using a + javascript-capable browser. +
+ ++ Applications that depend on a particular XML schema + can request + http://127.0.0.1:8888/xml/v2 for version 2 + of the statistics XML schema or + http://127.0.0.1:8888/xml/v3 for version 3. + If the requested schema is supported by the server, then + it will respond; if not, it will return a "page not found" + error. +
+ ++ Broken-out subsets of the statistics can be viewed at + http://127.0.0.1:8888/xml/v3/status + (server uptime and last reconfiguration time), + http://127.0.0.1:8888/xml/v3/server + (server and resolver statistics), + http://127.0.0.1:8888/xml/v3/zones + (zone statistics), + http://127.0.0.1:8888/xml/v3/net + (network status and socket statistics), + http://127.0.0.1:8888/xml/v3/mem + (memory manager statistics), + http://127.0.0.1:8888/xml/v3/tasks + (task manager statistics), and + http://127.0.0.1:8888/xml/v3/traffic + (traffic sizes). +
+ ++ The full set of statistics can also be read in JSON format at + http://127.0.0.1:8888/json, + with the broken-out subsets at + http://127.0.0.1:8888/json/v1/status + (server uptime and last reconfiguration time), + http://127.0.0.1:8888/json/v1/server + (server and resolver statistics), + http://127.0.0.1:8888/json/v1/zones + (zone statistics), + http://127.0.0.1:8888/json/v1/net + (network status and socket statistics), + http://127.0.0.1:8888/json/v1/mem + (memory manager statistics), + http://127.0.0.1:8888/json/v1/tasks + (task manager statistics), and + http://127.0.0.1:8888/json/v1/traffic + (traffic sizes). +
+trusted-keys { + (+ +domain_nameflagsprotocolalgorithmkey_data; ) + ... +} ; +
+ The trusted-keys statement defines + DNSSEC security roots. DNSSEC is described in the section called “DNSSEC”. A security root is defined when the + public key for a non-authoritative zone is known, but + cannot be securely obtained through DNS, either because + it is the DNS root zone or because its parent zone is + unsigned. Once a key has been configured as a trusted + key, it is treated as if it had been validated and + proven secure. The resolver attempts DNSSEC validation + on all DNS data in subdomains of a security root. +
++ All keys (and corresponding zones) listed in + trusted-keys are deemed to exist regardless + of what parent zones say. Similarly for all keys listed in + trusted-keys only those keys are + used to validate the DNSKEY RRset. The parent's DS RRset + will not be used. +
++ The trusted-keys statement can contain + multiple key entries, each consisting of the key's + domain name, flags, protocol, algorithm, and the Base-64 + representation of the key data. + Spaces, tabs, newlines and carriage returns are ignored + in the key data, so the configuration may be split up into + multiple lines. +
+
+ trusted-keys may be set at the top level
+ of named.conf or within a view. If it is
+ set in both places, they are additive: keys defined at the top
+ level are inherited by all views, but keys defined in a view
+ are only used within that view.
+
+ Validation below specified names can be temporarily disabled + by using rndc nta. +
+managed-keys { + (+ +domain_nameinitial_keyflagsprotocolalgorithmkey_data; ) + ... +} ; +
+ The managed-keys statement, like + trusted-keys, defines DNSSEC + security roots. The difference is that + managed-keys can be kept up to date + automatically, without intervention from the resolver + operator. +
++ Suppose, for example, that a zone's key-signing + key was compromised, and the zone owner had to revoke and + replace the key. A resolver which had the old key in a + trusted-keys statement would be + unable to validate this zone any longer; it would + reply with a SERVFAIL response code. This would + continue until the resolver operator had updated the + trusted-keys statement with the new key. +
++ If, however, the zone were listed in a + managed-keys statement instead, then the + zone owner could add a "stand-by" key to the zone in advance. + named would store the stand-by key, and + when the original key was revoked, named + would be able to transition smoothly to the new key. It would + also recognize that the old key had been revoked, and cease + using that key to validate answers, minimizing the damage that + the compromised key could do. +
+
+ A managed-keys statement contains a list of
+ the keys to be managed, along with information about how the
+ keys are to be initialized for the first time. The only
+ initialization method currently supported (as of
+ BIND 9.7.0) is initial-key.
+ This means the managed-keys statement must
+ contain a copy of the initializing key. (Future releases may
+ allow keys to be initialized by other methods, eliminating this
+ requirement.)
+
+ Consequently, a managed-keys statement
+ appears similar to a trusted-keys, differing
+ in the presence of the second field, containing the keyword
+ initial-key. The difference is, whereas the
+ keys listed in a trusted-keys continue to be
+ trusted until they are removed from
+ named.conf, an initializing key listed
+ in a managed-keys statement is only trusted
+ once: for as long as it takes to load the
+ managed key database and start the RFC 5011 key maintenance
+ process.
+
+ The first time named runs with a managed key
+ configured in named.conf, it fetches the
+ DNSKEY RRset directly from the zone apex, and validates it
+ using the key specified in the managed-keys
+ statement. If the DNSKEY RRset is validly signed, then it is
+ used as the basis for a new managed keys database.
+
+ From that point on, whenever named runs, it + sees the managed-keys statement, checks to + make sure RFC 5011 key maintenance has already been initialized + for the specified domain, and if so, it simply moves on. The + key specified in the managed-keys + statement is not used to validate answers; it has been + superseded by the key or keys stored in the managed keys database. +
++ The next time named runs after a name + has been removed from the + managed-keys statement, the corresponding + zone will be removed from the managed keys database, + and RFC 5011 key maintenance will no longer be used for that + domain. +
++ In the current implementation, the managed keys database + is stored as a master-format zone file. +
+
+ On servers which do not use views, this file is named
+ managed-keys.bind. When views are in
+ use, there will be a separate managed keys database for each
+ view; the filename will be the view name (or, if a view name
+ contains characters which would make it illegal as a filename,
+ a hash of the view name), followed by
+ the suffix .mkeys.
+
+ When the key database is changed, the zone is updated.
+ As with any other dynamic zone, changes will be written
+ into a journal file, e.g.,
+ managed-keys.bind.jnl or
+ internal.mkeys.jnl.
+ Changes are committed to the master file as soon as
+ possible afterward; this will usually occur within 30
+ seconds. So, whenever named is using
+ automatic key maintenance, the zone file and journal file
+ can be expected to exist in the working directory.
+ (For this reason among others, the working directory
+ should be always be writable by named.)
+
+ If the dnssec-validation option is
+ set to auto, named
+ will automatically initialize a managed key for the
+ root zone. Similarly, if the dnssec-lookaside
+ option is set to auto,
+ named will automatically initialize
+ a managed key for the zone dlv.isc.org.
+ (Note: The ISC DLV service is expected to cease operation by
+ the end of 2017.) In both cases, the key that is used to
+ initialize the key maintenance process is built into
+ named, and can be overridden from
+ bindkeys-file.
+
view+ +view_name[class] { + match-clients {address_match_list} ; + match-destinations {address_match_list} ; + match-recursive-onlyyes_or_no; + [view_option; ... ] + [zone_statement; ... ] +} ; +
+ The view statement is a powerful + feature + of BIND 9 that lets a name server + answer a DNS query differently + depending on who is asking. It is particularly useful for + implementing + split DNS setups without having to run multiple servers. +
+ +
+ Each view statement defines a view
+ of the
+ DNS namespace that will be seen by a subset of clients. A client
+ matches
+ a view if its source IP address matches the
+ address_match_list of the view's
+ match-clients clause and its
+ destination IP address matches
+ the address_match_list of the
+ view's
+ match-destinations clause. If not
+ specified, both
+ match-clients and match-destinations
+ default to matching all addresses. In addition to checking IP
+ addresses
+ match-clients and match-destinations
+ can also take keys which provide an
+ mechanism for the
+ client to select the view. A view can also be specified
+ as match-recursive-only, which
+ means that only recursive
+ requests from matching clients will match that view.
+ The order of the view statements is
+ significant —
+ a client request will be resolved in the context of the first
+ view that it matches.
+
+ Zones defined within a view + statement will + only be accessible to clients that match the view. + By defining a zone of the same name in multiple views, different + zone data can be given to different clients, for example, + "internal" + and "external" clients in a split DNS setup. +
+ ++ Many of the options given in the options statement + can also be used within a view + statement, and then + apply only when resolving queries with that view. When no + view-specific + value is given, the value in the options statement + is used as a default. Also, zone options can have default values + specified + in the view statement; these + view-specific defaults + take precedence over those in the options statement. +
+ ++ Views are class specific. If no class is given, class IN + is assumed. Note that all non-IN views must contain a hint zone, + since only the IN class has compiled-in default hints. +
+ ++ If there are no view statements in + the config + file, a default view that matches any client is automatically + created + in class IN. Any zone statements + specified on + the top level of the configuration file are considered to be part + of + this default view, and the options + statement will + apply to the default view. If any explicit view + statements are present, all zone + statements must + occur inside view statements. +
+ ++ Here is an example of a typical split DNS setup implemented + using view statements: +
+ +view "internal" {
+ // This should match our internal networks.
+ match-clients { 10.0.0.0/8; };
+
+ // Provide recursive service to internal
+ // clients only.
+ recursion yes;
+
+ // Provide a complete view of the example.com
+ // zone including addresses of internal hosts.
+ zone "example.com" {
+ type master;
+ file "example-internal.db";
+ };
+};
+
+view "external" {
+ // Match all clients not matched by the
+ // previous view.
+ match-clients { any; };
+
+ // Refuse recursive service to external clients.
+ recursion no;
+
+ // Provide a restricted view of the example.com
+ // zone containing only publicly accessible hosts.
+ zone "example.com" {
+ type master;
+ file "example-external.db";
+ };
+};
+
+
+ zone+ +zone_name[class] { + type master ; + [ allow-query {address_match_list} ; ] + [ allow-query-on {address_match_list} ; ] + [ allow-transfer {address_match_list} ; ] + [ allow-update {address_match_list} ; ] + [ update-check-kskyes_or_no; ] + [ dnssec-dnskey-kskonlyyes_or_no; ] + [ dnssec-loadkeys-intervalnumber; ] + [ update-policylocal| {update_policy_rule; ... } ; ] + [ also-notify [ portip_port] [ dscpip_dscp] { + (masters_list|ip_addr[ portip_port] ) [ keykey_name] ; + ... + } ; ] + [ check-names (warn|fail|ignore) ; ] + [ check-mx (warn|fail|ignore) ; ] + [ check-wildcardyes_or_no; ] + [ check-spf (warn|ignore); ] + [ check-integrityyes_or_no; ] + [ dialupdialup_option; ] + [ filestring; ] + [ masterfile-format (text|raw|map) ; ] + [ journalstring; ] + [ max-journal-sizesize_spec; ] + [ forward (only|first) ; ] + [ forwarders { [ip_addr[ portip_port] [ dscpip_dscp] ; ... ] } ; ] + [ ixfr-basestring; ] + [ ixfr-from-differencesyes_or_no; ] + [ ixfr-tmp-filestring; ] + [ maintain-ixfr-baseyes_or_no; ] + [ max-ixfr-log-sizenumber; ] + [ max-transfer-idle-outnumber; ] + [ max-transfer-time-outnumber; ] + [ notifyyes_or_no|explicit|master-only; ] + [ notify-delayseconds; ] + [ notify-to-soayes_or_no; ] + [ pubkeynumbernumbernumberstring; ] + [ notify-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ notify-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ zone-statistics (full|terse|none) ; ] + [ sig-validity-intervalnumber[number] ; ] + [ sig-signing-nodesnumber; ] + [ sig-signing-signaturesnumber; ] + [ sig-signing-typenumber; ] + [ databasestring; ] + [ min-refresh-timenumber; ] + [ max-refresh-timenumber; ] + [ min-retry-timenumber; ] + [ max-retry-timenumber; ] + [ key-directorypath_name; ] + [ auto-dnssec (allow|maintain|off) ; ] + [ inline-signingyes_or_no; ] + [ zero-no-soa-ttlyes_or_no; ] + [ serial-update-method (increment|unixtime|date) ; ] + [ max-zone-ttlnumber; ] +} ; + +zonezone_name[class] { + type slave ; + [ allow-notify {address_match_list} ; ] + [ allow-query {address_match_list} ; ] + [ allow-query-on {address_match_list} ; ] + [ allow-transfer {address_match_list} ; ] + [ allow-update-forwarding {address_match_list} ; ] + [ dnssec-update-mode (maintain|no-resign); ] + [ update-check-kskyes_or_no; ] + [ dnssec-dnskey-kskonlyyes_or_no; ] + [ dnssec-loadkeys-intervalnumber; ] + [ dnssec-secure-to-insecureyes_or_no; ] + [ try-tcp-refreshyes_or_no; ] + [ also-notify [ portip_port] [ dscpip_dscp] { + (masters_list|ip_addr[ portip_port] ) [ keykey_name] ; + ... + } ; ] + [ check-names (warn|fail|ignore) ; ] + [ dialupdialup_option; ] + [ filestring; ] + [ masterfile-format (text|raw|map) ; ] + [ journalstring; ] + [ max-journal-sizesize_spec; ] + [ forward (only|first) ; ] + [ forwarders { [ip_addr[ portip_port] [ dscpip_dscp] ; ... } ; ] + [ ixfr-basestring; ] + [ ixfr-from-differencesyes_or_no; ] + [ ixfr-tmp-filestring; ] + [ request-ixfryes_or_no; ] + [ maintain-ixfr-baseyes_or_no; ] + [ masters [ portip_port] [ dscpip_dscp] { + (masters_list|ip_addr[ portip_port] ) [ keykey_name] ; + ... + } ; ] + [ max-ixfr-log-sizenumber; ] + [ max-transfer-idle-innumber; ] + [ max-transfer-idle-outnumber; ] + [ max-transfer-time-innumber; ] + [ max-transfer-time-outnumber; ] + [ notify (yes_or_no|explicit|master-only) ; ] + [ notify-delayseconds; ] + [ notify-to-soayes_or_no; ] + [ pubkeynumbernumbernumberstring; ] + [ transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ alt-transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ alt-transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ use-alt-transfer-sourceyes_or_no; ] + [ notify-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ notify-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ zone-statistics (full|terse|none) ; ] + [ sig-validity-intervalnumber[number] ; ] + [ sig-signing-nodesnumber; ] + [ sig-signing-signaturesnumber; ] + [ sig-signing-typenumber; ] + [ databasestring; ] + [ min-refresh-timenumber; ] + [ max-refresh-timenumber; ] + [ min-retry-timenumber; ] + [ max-retry-timenumber; ] + [ key-directorypath_name; ] + [ auto-dnssec (allow|maintain|off) ; ] + [ inline-signingyes_or_no; ] + [ multi-masteryes_or_no; ] + [ zero-no-soa-ttlyes_or_no; ] +} ; + +zonezone_name[class] { + type hint; + filestring; + [ delegation-onlyyes_or_no; ] + [ check-names (warn|fail|ignore) ; ] // Not Implemented. +} ; + +zonezone_name[class] { + type stub; + [ allow-query {address_match_list} ; ] + [ allow-query-on {address_match_list} ; ] + [ check-names (warn|fail|ignore) ; ] + [ dialupdialup_option; ] + [ delegation-onlyyes_or_no; ] + [ filestring; ] + [ masterfile-format (text|raw|map) ; ] + [ forward (only|first) ; ] + [ forwarders { [ip_addr[ portip_port] [ dscpip_dscp] ; ... ] } ; ] + [ masters [ portip_port] [ dscpip_dscp] { + (masters_list|ip_addr[ portip_port] ) [ keykey_name] ; + ... + } ; ] + [ max-transfer-idle-innumber; ] + [ max-transfer-time-innumber; ] + [ pubkeynumbernumbernumberstring; ] + [ transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ alt-transfer-source (ip4_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ alt-transfer-source-v6 (ip6_addr|*) + [ portip_port] [ dscpip_dscp] ; ] + [ use-alt-transfer-sourceyes_or_no; ] + [ zone-statistics (full|terse|none) ; ] + [ databasestring; ] + [ min-refresh-timenumber; ] + [ max-refresh-timenumber; ] + [ min-retry-timenumber; ] + [ max-retry-timenumber; ] + [ multi-masteryes_or_no; ] +} ; + +zonezone_name[class] { + type static-stub; + [ allow-query {address_match_list} ; ] + [ server-addresses { [ip_addr; ... } ; ] + [ server-names { [namelist] } ; ] + [ zone-statistics (full|terse|none) ; ] +} ; + +zonezone_name[class] { + type forward; + [ forward (only|first) ; ] + [ forwarders { [ip_addr[ portip_port] [ dscpip_dscp] ; ... } ; ] + [ delegation-onlyyes_or_no; ] +} ; + +zone"."[class] { + type redirect; + [ filestring; ] + [ masters [ portip_port] [ dscpip_dscp] { + (masters_list|ip_addr[ portip_port] ) [ keykey_name] ; + ... + } ; ] + [ masterfile-format (text|raw|map) ; ] + [ allow-query {address_match_list} ; ] + [ max-zone-ttlnumber; ] +} ; + +zonezone_name[class] { + type delegation-only; +} ; + +zonezone_name[class] { + [ in-viewstring; ] +} ; + +
+ The type keyword is required
+ for the zone configuration unless
+ it is an in-view configuration. Its
+ acceptable values include: delegation-only,
+ forward, hint,
+ master, redirect,
+ slave, static-stub,
+ and stub.
+
|
+
+ |
+
+ + The server has a master copy of the data + for the zone and will be able to provide authoritative + answers for + it. + + |
+
|
+
+ |
+
+
+ A slave zone is a replica of a master
+ zone. The masters list
+ specifies one or more IP addresses
+ of master servers that the slave contacts to update
+ its copy of the zone.
+ Masters list elements can also be names of other
+ masters lists.
+ By default, transfers are made from port 53 on the
+ servers; this can
+ be changed for all servers by specifying a port number
+ before the
+ list of IP addresses, or on a per-server basis after
+ the IP address.
+ Authentication to the master can also be done with
+ per-server TSIG keys.
+ If a file is specified, then the
+ replica will be written to this file whenever the zone
+ is changed,
+ and reloaded from this file on a server restart. Use
+ of a file is
+ recommended, since it often speeds server startup and
+ eliminates
+ a needless waste of bandwidth. Note that for large
+ numbers (in the
+ tens or hundreds of thousands) of zones per server, it
+ is best to
+ use a two-level naming scheme for zone filenames. For
+ example,
+ a slave server for the zone |
+
|
+
+ |
+
+ + A stub zone is similar to a slave zone, + except that it replicates only the NS records of a + master zone instead + of the entire zone. Stub zones are not a standard part + of the DNS; + they are a feature specific to the BIND implementation. + + +
+ Stub zones can be used to eliminate the need for glue
+ NS record
+ in a parent zone at the expense of maintaining a stub
+ zone entry and
+ a set of name server addresses in
+ Stub zones can also be used as a way of forcing the
+ resolution
+ of a given domain to use a particular set of
+ authoritative servers.
+ For example, the caching name servers on a private
+ network using
+ RFC1918 addressing may be configured with stub zones
+ for
+ |
+
|
+
+ |
+
+ + A static-stub zone is similar to a stub zone + with the following exceptions: + the zone data is statically configured, rather + than transferred from a master server; + when recursion is necessary for a query that + matches a static-stub zone, the locally + configured data (nameserver names and glue addresses) + is always used even if different authoritative + information is cached. + ++ Zone data is configured via the + server-addresses and + server-names zone options. + ++ The zone data is maintained in the form of NS + and (if necessary) glue A or AAAA RRs + internally, which can be seen by dumping zone + databases by rndc dumpdb -all. + The configured RRs are considered local configuration + parameters rather than public data. + Non recursive queries (i.e., those with the RD + bit off) to a static-stub zone are therefore + prohibited and will be responded with REFUSED. + ++ Since the data is statically configured, no + zone maintenance action takes place for a static-stub + zone. + For example, there is no periodic refresh + attempt, and an incoming notify message + will be rejected with an rcode of NOTAUTH. + ++ Each static-stub zone is configured with + internally generated NS and (if necessary) + glue A or AAAA RRs + + |
+
|
+
+ |
+
+ + A "forward zone" is a way to configure + forwarding on a per-domain basis. A zone statement + of type forward can + contain a forward + and/or forwarders + statement, + which will apply to queries within the domain given by + the zone + name. If no forwarders + statement is present or + an empty list for forwarders is given, then no + forwarding will be done for the domain, canceling the + effects of + any forwarders in the options statement. Thus + if you want to use this type of zone to change the + behavior of the + global forward option + (that is, "forward first" + to, then "forward only", or vice versa, but want to + use the same + servers as set globally) you need to re-specify the + global forwarders. + + |
+
|
+
+ |
+
+ + The initial set of root name servers is + specified using a "hint zone". When the server starts + up, it uses + the root hints to find a root name server and get the + most recent + list of root name servers. If no hint zone is + specified for class + IN, the server uses a compiled-in default set of root + servers hints. + Classes other than IN have no built-in defaults hints. + + |
+
|
+
+ |
+
+ + Redirect zones are used to provide answers to + queries when normal resolution would result in + NXDOMAIN being returned. + Only one redirect zone is supported + per view. allow-query can be + used to restrict which clients see these answers. + ++ If the client has requested DNSSEC records (DO=1) and + the NXDOMAIN response is signed then no substitution + will occur. + +
+ To redirect all NXDOMAIN responses to
+ 100.100.100.2 and
+ 2001:ffff:ffff::100.100.100.2, one would
+ configure a type redirect zone named ".",
+ with the zone file containing wildcard records
+ that point to the desired addresses:
+ + To redirect all Spanish names (under .ES) one + would use similar entries but with the names + "*.ES." instead of "*.". To redirect all + commercial Spanish names (under COM.ES) one + would use wildcard entries called "*.COM.ES.". + ++ Note that the redirect zone supports all + possible types; it is not limited to A and + AAAA records. + +
+ If a redirect zone is configured with a
+ + Because redirect zones are not referenced + directly by name, they are not kept in the + zone lookup table with normal master and slave + zones. To reload a redirect zone, use + rndc reload -redirect, + and to retransfer a redirect zone configured + as slave, use + rndc retransfer -redirect. + When using rndc reload + without specifying a zone name, redirect zones + will be reloaded along with other zones. + + |
+
|
+
+ |
+
+ + This is used to enforce the delegation-only + status of infrastructure zones (e.g. COM, + NET, ORG). Any answer that is received + without an explicit or implicit delegation + in the authority section will be treated + as NXDOMAIN. This does not apply to the + zone apex. This should not be applied to + leaf zones. + +
+ + See caveats in root-delegation-only. + + |
+
+ The zone's name may optionally be followed by a class. If
+ a class is not specified, class IN (for Internet),
+ is assumed. This is correct for the vast majority of cases.
+
+ The hesiod class is
+ named for an information service from MIT's Project Athena. It
+ is
+ used to share information about various systems databases, such
+ as users, groups, printers and so on. The keyword
+ HS is
+ a synonym for hesiod.
+
+ Another MIT development is Chaosnet, a LAN protocol created
+ in the mid-1970s. Zone data for it can be specified with the CHAOS class.
+
+ See the description of + allow-notify in the section called “Access Control”. +
++ See the description of + allow-query in the section called “Access Control”. +
++ See the description of + allow-query-on in the section called “Access Control”. +
++ See the description of allow-transfer + in the section called “Access Control”. +
++ See the description of allow-update + in the section called “Access Control”. +
++ Specifies a "Simple Secure Update" policy. See + the section called “Dynamic Update Policies”. +
++ See the description of allow-update-forwarding + in the section called “Access Control”. +
+
+ Only meaningful if notify
+ is
+ active for this zone. The set of machines that will
+ receive a
+ DNS NOTIFY message
+ for this zone is made up of all the listed name servers
+ (other than
+ the primary master) for the zone plus any IP addresses
+ specified
+ with also-notify. A port
+ may be specified
+ with each also-notify
+ address to send the notify
+ messages to a port other than the default of 53.
+ A TSIG key may also be specified to cause the
+ NOTIFY to be signed by the
+ given key.
+ also-notify is not
+ meaningful for stub zones.
+ The default is the empty list.
+
+ This option is used to restrict the character set and + syntax of + certain domain names in master files and/or DNS responses + received from the + network. The default varies according to zone type. For master zones the default is fail. For slave + zones the default is warn. + It is not implemented for hint zones. +
++ See the description of + check-mx in the section called “Boolean Options”. +
++ See the description of + check-spf in the section called “Boolean Options”. +
++ See the description of + check-wildcard in the section called “Boolean Options”. +
++ See the description of + check-integrity in the section called “Boolean Options”. +
++ See the description of + check-sibling in the section called “Boolean Options”. +
++ See the description of + zero-no-soa-ttl in the section called “Boolean Options”. +
++ See the description of + update-check-ksk in the section called “Boolean Options”. +
++ See the description of + dnssec-loadkeys-interval in the section called “options Statement Definition and + Usage”. +
++ See the description of + dnssec-update-mode in the section called “options Statement Definition and + Usage”. +
++ See the description of + dnssec-dnskey-kskonly in the section called “Boolean Options”. +
++ See the description of + try-tcp-refresh in the section called “Boolean Options”. +
++ Specify the type of database to be used for storing the + zone data. The string following the database keyword + is interpreted as a list of whitespace-delimited words. + The first word + identifies the database type, and any subsequent words are + passed + as arguments to the database to be interpreted in a way + specific + to the database type. +
+
+ The default is "rbt", BIND 9's
+ native in-memory
+ red-black-tree database. This database does not take
+ arguments.
+
+ Other values are possible if additional database drivers + have been linked into the server. Some sample drivers are + included + with the distribution but none are linked in by default. +
++ See the description of + dialup in the section called “Boolean Options”. +
+
+ The flag only applies to forward, hint and stub
+ zones. If set to yes,
+ then the zone will also be treated as if it is
+ also a delegation-only type zone.
+
+ See caveats in root-delegation-only. +
++ Only meaningful if the zone has a forwarders + list. The only value causes + the lookup to fail + after trying the forwarders and getting no answer, while first would + allow a normal lookup to be tried. +
++ Used to override the list of global forwarders. + If it is not specified in a zone of type forward, + no forwarding is done for the zone and the global options are + not used. +
+
+ Was used in BIND 8 to
+ specify the name
+ of the transaction log (journal) file for dynamic update
+ and IXFR.
+ BIND 9 ignores the option
+ and constructs the name of the journal
+ file by appending ".jnl"
+ to the name of the
+ zone file.
+
+ Was an undocumented option in BIND 8. + Ignored in BIND 9. +
+
+ Allow the default journal's filename to be overridden.
+ The default is the zone's filename with ".jnl" appended.
+ This is applicable to master and slave zones.
+
+ See the description of + max-journal-size in the section called “Server Resource Limits”. +
++ See the description of + max-records in the section called “Server Resource Limits”. +
++ See the description of + max-transfer-time-in in the section called “Zone Transfers”. +
++ See the description of + max-transfer-idle-in in the section called “Zone Transfers”. +
++ See the description of + max-transfer-time-out in the section called “Zone Transfers”. +
++ See the description of + max-transfer-idle-out in the section called “Zone Transfers”. +
++ See the description of + notify in the section called “Boolean Options”. +
++ See the description of + notify-delay in the section called “Tuning”. +
++ See the description of + notify-to-soa in + the section called “Boolean Options”. +
++ In BIND 8, this option was + intended for specifying + a public zone key for verification of signatures in DNSSEC + signed + zones when they are loaded from disk. BIND 9 does not verify signatures + on load and ignores the option. +
++ See the description of + zone-statistics in + the section called “options Statement Definition and + Usage”. +
++ Only meaningful for static-stub zones. + This is a list of IP addresses to which queries + should be sent in recursive resolution for the + zone. + A non empty list for this option will internally + configure the apex NS RR with associated glue A or + AAAA RRs. +
++ For example, if "example.com" is configured as a + static-stub zone with 192.0.2.1 and 2001:db8::1234 + in a server-addresses option, + the following RRs will be internally configured. +
+example.com. NS example.com. +example.com. A 192.0.2.1 +example.com. AAAA 2001:db8::1234+
+ These records are internally used to resolve + names under the static-stub zone. + For instance, if the server receives a query for + "www.example.com" with the RD bit on, the server + will initiate recursive resolution and send + queries to 192.0.2.1 and/or 2001:db8::1234. +
++ Only meaningful for static-stub zones. + This is a list of domain names of nameservers that + act as authoritative servers of the static-stub + zone. + These names will be resolved to IP addresses when + named needs to send queries to + these servers. + To make this supplemental resolution successful, + these names must not be a subdomain of the origin + name of static-stub zone. + That is, when "example.net" is the origin of a + static-stub zone, "ns.example" and + "master.example.com" can be specified in the + server-names option, but + "ns.example.net" cannot, and will be rejected by + the configuration parser. +
++ A non empty list for this option will internally + configure the apex NS RR with the specified names. + For example, if "example.com" is configured as a + static-stub zone with "ns1.example.net" and + "ns2.example.net" + in a server-names option, + the following RRs will be internally configured. +
+example.com. NS ns1.example.net. +example.com. NS ns2.example.net. ++
+ These records are internally used to resolve + names under the static-stub zone. + For instance, if the server receives a query for + "www.example.com" with the RD bit on, the server + initiate recursive resolution, + resolve "ns1.example.net" and/or + "ns2.example.net" to IP addresses, and then send + queries to (one or more of) these addresses. +
++ See the description of + sig-validity-interval in the section called “Tuning”. +
++ See the description of + sig-signing-nodes in the section called “Tuning”. +
++ See the description of + sig-signing-signatures in the section called “Tuning”. +
++ See the description of + sig-signing-type in the section called “Tuning”. +
++ See the description of + transfer-source in the section called “Zone Transfers”. +
++ See the description of + transfer-source-v6 in the section called “Zone Transfers”. +
++ See the description of + alt-transfer-source in the section called “Zone Transfers”. +
++ See the description of + alt-transfer-source-v6 in the section called “Zone Transfers”. +
++ See the description of + use-alt-transfer-source in the section called “Zone Transfers”. +
++ See the description of + notify-source in the section called “Zone Transfers”. +
++ See the description of + notify-source-v6 in the section called “Zone Transfers”. +
++ See the description in the section called “Tuning”. +
+
+ See the description of
+ ixfr-from-differences in the section called “Boolean Options”.
+ (Note that the ixfr-from-differences
+ master and
+ slave choices are not
+ available at the zone level.)
+
+ See the description of + key-directory in the section called “options Statement Definition and + Usage”. +
++ See the description of + auto-dnssec in + the section called “options Statement Definition and + Usage”. +
++ See the description of + serial-update-method in + the section called “options Statement Definition and + Usage”. +
+
+ If yes, this enables
+ "bump in the wire" signing of a zone, where a
+ unsigned zone is transferred in or loaded from
+ disk and a signed version of the zone is served,
+ with possibly, a different serial number. This
+ behavior is disabled by default.
+
+ See the description of multi-master in + the section called “Boolean Options”. +
++ See the description of masterfile-format + in the section called “Tuning”. +
++ See the description of max-zone-ttl + in the section called “options Statement Definition and + Usage”. +
++ See the description of + dnssec-secure-to-insecure in the section called “Boolean Options”. +
+BIND 9 supports two alternative + methods of granting clients the right to perform + dynamic updates to a zone, configured by the + allow-update and + update-policy option, respectively. +
++ The allow-update clause works the + same way as in previous versions of BIND. + It grants given clients the permission to update any + record of any name in the zone. +
++ The update-policy clause + allows more fine-grained control over what updates are + allowed. A set of rules is specified, where each rule + either grants or denies permissions for one or more + names to be updated by one or more identities. If + the dynamic update request message is signed (that is, + it includes either a TSIG or SIG(0) record), the + identity of the signer can be determined. +
++ Rules are specified in the update-policy + zone option, and are only meaningful for master zones. + When the update-policy statement + is present, it is a configuration error for the + allow-update statement to be + present. The update-policy statement + only examines the signer of a message; the source + address is not relevant. +
+
+ There is a pre-defined update-policy
+ rule which can be switched on with the command
+ update-policy local;.
+ Switching on this rule in a zone causes
+ named to generate a TSIG session
+ key and place it in a file, and to allow that key
+ to update the zone. (By default, the file is
+ /var/run/named/session.key, the key
+ name is "local-ddns" and the key algorithm is HMAC-SHA256,
+ but these values are configurable with the
+ session-keyfile,
+ session-keyname and
+ session-keyalg options, respectively).
+
+ A client running on the local system, and with appropriate + permissions, may read that file and use the key to sign update + requests. The zone's update policy will be set to allow that + key to change any record within the zone. Assuming the + key name is "local-ddns", this policy is equivalent to: +
+ +update-policy { grant local-ddns zonesub any; };
+
+
+ + The command nsupdate -l sends update + requests to localhost, and signs them using the session key. +
+ ++ Other rule definitions look like this: +
+ ++( grant | deny )+ +identitynametype[name] [types] +
+ Each rule grants or denies privileges. Once a message has + successfully matched a rule, the operation is immediately + granted or denied and no further rules are examined. A rule + is matched when the signer matches the identity field, the + name matches the name field in accordance with the nametype + field, and the type matches the types specified in the type + field. +
+
+ No signer is required for tcp-self
+ or 6to4-self however the standard
+ reverse mapping / prefix conversion must match the identity
+ field.
+
+ The identity field specifies a name or a wildcard
+ name. Normally, this is the name of the TSIG or
+ SIG(0) key used to sign the update request. When a
+ TKEY exchange has been used to create a shared secret,
+ the identity of the shared secret is the same as the
+ identity of the key used to authenticate the TKEY
+ exchange. TKEY is also the negotiation method used
+ by GSS-TSIG, which establishes an identity that is
+ the Kerberos principal of the client, such as
+ "user@host.domain". When the
+ identity field specifies
+ a wildcard name, it is subject to DNS wildcard
+ expansion, so the rule will apply to multiple identities.
+ The identity field must
+ contain a fully-qualified domain name.
+
+ For nametypes krb5-self,
+ ms-self, krb5-subdomain,
+ and ms-subdomain the
+ identity field specifies
+ the Windows or Kerberos realm of the machine belongs to.
+
+ The nametype field has 13
+ values:
+ name, subdomain,
+ wildcard, self,
+ selfsub, selfwild,
+ krb5-self, ms-self,
+ krb5-subdomain,
+ ms-subdomain,
+ tcp-self, 6to4-self,
+ zonesub, and external.
+
|
+
+ |
+
+
+ Exact-match semantics. This rule matches
+ when the name being updated is identical
+ to the contents of the
+ |
+
|
+
+ |
+
+
+ This rule matches when the name being updated
+ is a subdomain of, or identical to, the
+ contents of the |
+
|
+
+ |
+
+ + This rule is similar to subdomain, except that + it matches when the name being updated is a + subdomain of the zone in which the + update-policy statement + appears. This obviates the need to type the zone + name twice, and enables the use of a standard + update-policy statement in + multiple zones without modification. + +
+ When this rule is used, the
+ |
+
|
+
+ |
+
+
+ The |
+
|
+
+ |
+
+
+ This rule matches when the name being updated
+ matches the contents of the
+ |
+
|
+
+ |
+
+
+ This rule is similar to |
+
|
+
+ |
+
+
+ This rule is similar to |
+
|
+
+ |
+
+
+ This rule takes a Windows machine principal
+ (machine$@REALM) for machine in REALM and
+ and converts it machine.realm allowing the machine
+ to update machine.realm. The REALM to be matched
+ is specified in the |
+
|
+
+ |
+
+
+ This rule takes a Windows machine principal
+ (machine$@REALM) for machine in REALM and
+ converts it to machine.realm allowing the machine
+ to update subdomains of machine.realm. The REALM
+ to be matched is specified in the
+ |
+
|
+
+ |
+
+
+ This rule takes a Kerberos machine principal
+ (host/machine@REALM) for machine in REALM and
+ and converts it machine.realm allowing the machine
+ to update machine.realm. The REALM to be matched
+ is specified in the |
+
|
+
+ |
+
+
+ This rule takes a Kerberos machine principal
+ (host/machine@REALM) for machine in REALM and
+ converts it to machine.realm allowing the machine
+ to update subdomains of machine.realm. The REALM
+ to be matched is specified in the
+ |
+
|
+
+ |
+
+ + Allow updates that have been sent via TCP and + for which the standard mapping from the initiating + IP address into the IN-ADDR.ARPA and IP6.ARPA + namespaces match the name to be updated. + +
+
+ Note+ It is theoretically possible to spoof these TCP + sessions. + |
+
|
+
+ |
+
+ + Allow the 6to4 prefix to be update by any TCP + connection from the 6to4 network or from the + corresponding IPv4 address. This is intended + to allow NS or DNAME RRsets to be added to the + reverse tree. + +
+
+ Note+ It is theoretically possible to spoof these TCP + sessions. + |
+
|
+
+ |
+
+ + This rule allows named + to defer the decision of whether to allow a + given update to an external daemon. + +
+ The method of communicating with the daemon is
+ specified in the + Requests to the external daemon are sent over the + UNIX-domain socket as datagrams with the following + format: + ++ Protocol version number (4 bytes, network byte order, currently 1) + Request length (4 bytes, network byte order) + Signer (null-terminated string) + Name (null-terminated string) + TCP source address (null-terminated string) + Rdata type (null-terminated string) + Key (null-terminated string) + TKEY token length (4 bytes, network byte order) + TKEY token (remainder of packet)+ + The daemon replies with a four-byte value in + network byte order, containing either 0 or 1; 0 + indicates that the specified update is not + permitted, and 1 indicates that it is. + + |
+
+ In all cases, the name
+ field must specify a fully-qualified domain name.
+
+ If no types are explicitly specified, this rule matches + all types except RRSIG, NS, SOA, NSEC and NSEC3. Types + may be specified by name, including "ANY" (ANY matches + all types except NSEC and NSEC3, which can never be + updated). Note that when an attempt is made to delete + all records associated with a name, the rules are + checked for each existing record type. +
++ When multiple views are in use, a zone may be + referenced by more than one of them. Often, the views + will contain different zones with the same name, allowing + different clients to receive different answers for the same + queries. At times, however, it is desirable for multiple + views to contain identical zones. The + in-view zone option provides an efficient + way to do this: it allows a view to reference a zone that + was defined in a previously configured view. Example: +
+
+view internal {
+ match-clients { 10/8; };
+
+ zone example.com {
+ type master;
+ file "example-external.db";
+ };
+};
+
+view external {
+ match-clients { any; };
+
+ zone example.com {
+ in-view internal;
+ };
+};
+
+ + An in-view option cannot refer to a view + that is configured later in the configuration file. +
++ A zone statement which uses the + in-view option may not use any other + options with the exception of forward + and forwarders. (These options control + the behavior of the containing view, rather than changing + the zone object itself.) +
++ Zone level acls (e.g. allow-query, allow-transfer) and + other configuration details of the zone are all set + in the view the referenced zone is defined in. Care + need to be taken to ensure that acls are wide enough + for all views referencing the zone. +
++ An in-view zone cannot be used as a + response policy zone. +
++ An in-view zone is not intended to reference + a forward zone. +
++ This section, largely borrowed from RFC 1034, describes the + concept of a Resource Record (RR) and explains when each is used. + Since the publication of RFC 1034, several new RRs have been + identified + and implemented in the DNS. These are also included. +
++ A domain name identifies a node. Each node has a set of + resource information, which may be empty. The set of resource + information associated with a particular name is composed of + separate RRs. The order of RRs in a set is not significant and + need not be preserved by name servers, resolvers, or other + parts of the DNS. However, sorting of multiple RRs is + permitted for optimization purposes, for example, to specify + that a particular nearby server be tried first. See the section called “The sortlist Statement” and the section called “RRset Ordering”. +
+ ++ The components of a Resource Record are: +
+|
+ + owner name + + |
+
+ + The domain name where the RR is found. + + |
+
|
+ + type + + |
+
+ + An encoded 16-bit value that specifies + the type of the resource record. + + |
+
|
+ + TTL + + |
+
+ + The time-to-live of the RR. This field + is a 32-bit integer in units of seconds, and is + primarily used by + resolvers when they cache RRs. The TTL describes how + long a RR can + be cached before it should be discarded. + + |
+
|
+ + class + + |
+
+ + An encoded 16-bit value that identifies + a protocol family or instance of a protocol. + + |
+
|
+ + RDATA + + |
+
+ + The resource data. The format of the + data is type (and sometimes class) specific. + + |
+
+ The following are types of valid RRs: +
+|
+ + A + + |
+
+ + A host address. In the IN class, this is a + 32-bit IP address. Described in RFC 1035. + + |
+
|
+ + AAAA + + |
+
+ + IPv6 address. Described in RFC 1886. + + |
+
|
+ + A6 + + |
+
+ + IPv6 address. This can be a partial + address (a suffix) and an indirection to the name + where the rest of the + address (the prefix) can be found. Experimental. + Described in RFC 2874. + + |
+
|
+ + AFSDB + + |
+
+ + Location of AFS database servers. + Experimental. Described in RFC 1183. + + |
+
|
+ + APL + + |
+
+ + Address prefix list. Experimental. + Described in RFC 3123. + + |
+
|
+ + ATMA + + |
+
+ + ATM Address. + + |
+
|
+ + AVC + + |
+
+ + Application Visibility and Control record. + + |
+
|
+ + CAA + + |
+
+ + Identifies which Certificate Authorities can issue + certificates for this domain and what rules they + need to follow when doing so. Defined in RFC 6844. + + |
+
|
+ + CDNSKEY + + |
+
+ + Identifies which DNSKEY records should be published + as DS records in the parent zone. + + |
+
|
+ + CDS + + |
+
+ + Contains the set of DS records that should be published + by the parent zone. + + |
+
|
+ + CERT + + |
+
+ + Holds a digital certificate. + Described in RFC 2538. + + |
+
|
+ + CNAME + + |
+
+ + Identifies the canonical name of an alias. + Described in RFC 1035. + + |
+
|
+ + CSYNC + + |
+
+ + Child-to-Parent Synchronization in DNS as described + in RFC 7477. + + |
+
|
+ + DHCID + + |
+
+ + Is used for identifying which DHCP client is + associated with this name. Described in RFC 4701. + + |
+
|
+ + DLV + + |
+
+ + A DNS Look-aside Validation record which contains + the records that are used as trust anchors for + zones in a DLV namespace. Described in RFC 4431. + + |
+
|
+ + DNAME + + |
+
+ + Replaces the domain name specified with + another name to be looked up, effectively aliasing an + entire + subtree of the domain name space rather than a single + record + as in the case of the CNAME RR. + Described in RFC 2672. + + |
+
|
+ + DNSKEY + + |
+
+ + Stores a public key associated with a signed + DNS zone. Described in RFC 4034. + + |
+
|
+ + DS + + |
+
+ + Stores the hash of a public key associated with a + signed DNS zone. Described in RFC 4034. + + |
+
|
+ + EID + + |
+
+ + End Point Identifier. + + |
+
|
+ + EUI48 + + |
+
+ + A 48-bit EUI address. Described in RFC 7043. + + |
+
|
+ + EUI64 + + |
+
+ + A 64-bit EUI address. Described in RFC 7043. + + |
+
|
+ + GID + + |
+
+ + Reserved. + + |
+
|
+ + GPOS + + |
+
+ + Specifies the global position. Superseded by LOC. + + |
+
|
+ + HINFO + + |
+
+ + Identifies the CPU and OS used by a host. + Described in RFC 1035. + + |
+
|
+ + HIP + + |
+
+ + Host Identity Protocol Address. + Described in RFC 5205. + + |
+
|
+ + IPSECKEY + + |
+
+ + Provides a method for storing IPsec keying material in + DNS. Described in RFC 4025. + + |
+
|
+ + ISDN + + |
+
+ + Representation of ISDN addresses. + Experimental. Described in RFC 1183. + + |
+
|
+ + KEY + + |
+
+ + Stores a public key associated with a + DNS name. Used in original DNSSEC; replaced + by DNSKEY in DNSSECbis, but still used with + SIG(0). Described in RFCs 2535 and 2931. + + |
+
|
+ + KX + + |
+
+ + Identifies a key exchanger for this + DNS name. Described in RFC 2230. + + |
+
|
+ + L32 + + |
+
+ + Holds 32-bit Locator values for + Identifier-Locator Network Protocol. Described + in RFC 6742. + + |
+
|
+ + L64 + + |
+
+ + Holds 64-bit Locator values for + Identifier-Locator Network Protocol. Described + in RFC 6742. + + |
+
|
+ + LOC + + |
+
+ + For storing GPS info. Described in RFC 1876. + Experimental. + + |
+
|
+ + LP + + |
+
+ + Identifier-Locator Network Protocol. + Described in RFC 6742. + + |
+
|
+ + MB + + |
+
+ + Mail Box. Historical. + + |
+
|
+ + MD + + |
+
+ + Mail Destination. Historical. + + |
+
|
+ + MF + + |
+
+ + Mail Forwarder. Historical. + + |
+
|
+ + MG + + |
+
+ + Mail Group. Historical. + + |
+
|
+ + MINFO + + |
+
+ + Mail Information. + + |
+
|
+ + MR + + |
+
+ + Mail Rename. Historical. + + |
+
|
+ + MX + + |
+
+ + Identifies a mail exchange for the domain with + a 16-bit preference value (lower is better) + followed by the host name of the mail exchange. + Described in RFC 974, RFC 1035. + + |
+
|
+ + NAPTR + + |
+
+ + Name authority pointer. Described in RFC 2915. + + |
+
|
+ + NID + + |
+
+ + Holds values for Node Identifiers in + Identifier-Locator Network Protocol. Described + in RFC 6742. + + |
+
|
+ + NINFO + + |
+
+ + Contains zone status information. + + |
+
|
+ + NIMLOC + + |
+
+ + Nimrod Locator. + + |
+
|
+ + NSAP + + |
+
+ + A network service access point. + Described in RFC 1706. + + |
+
|
+ + NSAP-PTR + + |
+
+ + Historical. + + |
+
|
+ + NS + + |
+
+ + The authoritative name server for the + domain. Described in RFC 1035. + + |
+
|
+ + NSEC + + |
+
+ + Used in DNSSECbis to securely indicate that + RRs with an owner name in a certain name interval do + not exist in + a zone and indicate what RR types are present for an + existing name. + Described in RFC 4034. + + |
+
|
+ + NSEC3 + + |
+
+ + Used in DNSSECbis to securely indicate that + RRs with an owner name in a certain name + interval do not exist in a zone and indicate + what RR types are present for an existing + name. NSEC3 differs from NSEC in that it + prevents zone enumeration but is more + computationally expensive on both the server + and the client than NSEC. Described in RFC + 5155. + + |
+
|
+ + NSEC3PARAM + + |
+
+ + Used in DNSSECbis to tell the authoritative + server which NSEC3 chains are available to use. + Described in RFC 5155. + + |
+
|
+ + NULL + + |
+
+ + This is an opaque container. + + |
+
|
+ + NXT + + |
+
+ + Used in DNSSEC to securely indicate that + RRs with an owner name in a certain name interval do + not exist in + a zone and indicate what RR types are present for an + existing name. + Used in original DNSSEC; replaced by NSEC in + DNSSECbis. + Described in RFC 2535. + + |
+
|
+ + OPENPGPKEY + + |
+
+ + Used to hold an OPENPGPKEY. + + |
+
|
+ + PTR + + |
+
+ + A pointer to another part of the domain + name space. Described in RFC 1035. + + |
+
|
+ + PX + + |
+
+ + Provides mappings between RFC 822 and X.400 + addresses. Described in RFC 2163. + + |
+
|
+ + RKEY + + |
+
+ + Resource key. + + |
+
|
+ + RP + + |
+
+ + Information on persons responsible + for the domain. Experimental. Described in RFC 1183. + + |
+
|
+ + RRSIG + + |
+
+ + Contains DNSSECbis signature data. Described + in RFC 4034. + + |
+
|
+ + RT + + |
+
+ + Route-through binding for hosts that + do not have their own direct wide area network + addresses. + Experimental. Described in RFC 1183. + + |
+
|
+ + SIG + + |
+
+ + Contains DNSSEC signature data. Used in + original DNSSEC; replaced by RRSIG in + DNSSECbis, but still used for SIG(0). + Described in RFCs 2535 and 2931. + + |
+
|
+ + SINK + + |
+
+ + The kitchen sink record. + + |
+
|
+ + SMIMEA + + |
+
+ + The S/MIME Security Certificate Association. + + |
+
|
+ + SOA + + |
+
+ + Identifies the start of a zone of authority. + Described in RFC 1035. + + |
+
|
+ + SPF + + |
+
+ + Contains the Sender Policy Framework information + for a given email domain. Described in RFC 4408. + + |
+
|
+ + SRV + + |
+
+ + Information about well known network + services (replaces WKS). Described in RFC 2782. + + |
+
|
+ + SSHFP + + |
+
+ + Provides a way to securely publish a secure shell key's + fingerprint. Described in RFC 4255. + + |
+
|
+ + TA + + |
+
+ + Trust Anchor. Experimental. + + |
+
|
+ + TALINK + + |
+
+ + Trust Anchor Link. Experimental. + + |
+
|
+ + TLSA + + |
+
+ + Transport Layer Security Certificate Association. + Described in RFC 6698. + + |
+
|
+ + TXT + + |
+
+ + Text records. Described in RFC 1035. + + |
+
|
+ + UID + + |
+
+ + Reserved. + + |
+
|
+ + UINFO + + |
+
+ + Reserved. + + |
+
|
+ + UNSPEC + + |
+
+ + Reserved. Historical. + + |
+
|
+ + URI + + |
+
+ + Holds a URI. Described in RFC 7553. + + |
+
|
+ + WKS + + |
+
+ + Information about which well known + network services, such as SMTP, that a domain + supports. Historical. + + |
+
|
+ + X25 + + |
+
+ + Representation of X.25 network addresses. + Experimental. Described in RFC 1183. + + |
+
+ The following classes of resource records + are currently valid in the DNS: +
+|
+ + IN + + |
+
+ + The Internet. + + |
+
|
+ + CH + + |
+
+
+ Chaosnet, a LAN protocol created at MIT in the
+ mid-1970s.
+ Rarely used for its historical purpose, but reused for
+ BIND's
+ built-in server information zones, e.g.,
+ |
+
|
+ + HS + + |
+
+ + Hesiod, an information service + developed by MIT's Project Athena. It is used to share + information + about various systems databases, such as users, + groups, printers + and so on. + + |
+
+ The owner name is often implicit, rather than forming an + integral + part of the RR. For example, many name servers internally form + tree + or hash structures for the name space, and chain RRs off nodes. + The remaining RR parts are the fixed header (type, class, TTL) + which is consistent for all RRs, and a variable part (RDATA) + that + fits the needs of the resource being described. +
++ The meaning of the TTL field is a time limit on how long an + RR can be kept in a cache. This limit does not apply to + authoritative + data in zones; it is also timed out, but by the refreshing + policies + for the zone. The TTL is assigned by the administrator for the + zone where the data originates. While short TTLs can be used to + minimize caching, and a zero TTL prohibits caching, the + realities + of Internet performance suggest that these times should be on + the + order of days for the typical host. If a change can be + anticipated, + the TTL can be reduced prior to the change to minimize + inconsistency + during the change, and then increased back to its former value + following + the change. +
++ The data in the RDATA section of RRs is carried as a combination + of binary strings and domain names. The domain names are + frequently + used as "pointers" to other data in the DNS. +
++ RRs are represented in binary form in the packets of the DNS + protocol, and are usually represented in highly encoded form + when + stored in a name server or resolver. In the examples provided + in + RFC 1034, a style similar to that used in master files was + employed + in order to show the contents of RRs. In this format, most RRs + are shown on a single line, although continuation lines are + possible + using parentheses. +
++ The start of the line gives the owner of the RR. If a line + begins with a blank, then the owner is assumed to be the same as + that of the previous RR. Blank lines are often included for + readability. +
++ Following the owner, we list the TTL, type, and class of the + RR. Class and type use the mnemonics defined above, and TTL is + an integer before the type field. In order to avoid ambiguity + in + parsing, type and class mnemonics are disjoint, TTLs are + integers, + and the type mnemonic is always last. The IN class and TTL + values + are often omitted from examples in the interests of clarity. +
++ The resource data or RDATA section of the RR are given using + knowledge of the typical representation for the data. +
++ For example, we might show the RRs carried in a message as: +
+|
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
|
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
|
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
+ The MX RRs have an RDATA section which consists of a 16-bit + number followed by a domain name. The address RRs use a + standard + IP address format to contain a 32-bit internet address. +
++ The above example shows six RRs, with two RRs at each of three + domain names. +
++ Similarly we might see: +
+|
+
+ |
+
+
+ |
+
+
+ |
+
| + |
+
+ |
+
+
+ |
+
+ This example shows two addresses for
+ XX.LCS.MIT.EDU, each of a different class.
+
+ As described above, domain servers store information as a + series of resource records, each of which contains a particular + piece of information about a given domain name (which is usually, + but not always, a host). The simplest way to think of a RR is as + a typed pair of data, a domain name matched with a relevant datum, + and stored with some additional type information to help systems + determine when the RR is relevant. +
+ ++ MX records are used to control delivery of email. The data + specified in the record is a priority and a domain name. The + priority + controls the order in which email delivery is attempted, with the + lowest number first. If two priorities are the same, a server is + chosen randomly. If no servers at a given priority are responding, + the mail transport agent will fall back to the next largest + priority. + Priority numbers do not have any absolute meaning — they are + relevant + only respective to other MX records for that domain name. The + domain + name given is the machine to which the mail will be delivered. + It must have an associated address record + (A or AAAA) — CNAME is not sufficient. +
++ For a given domain, if there is both a CNAME record and an + MX record, the MX record is in error, and will be ignored. + Instead, + the mail will be delivered to the server specified in the MX + record + pointed to by the CNAME. + For example: +
+|
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
| + + | +
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
+
|
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
++ + | +
|
+
+ |
+
+
+ |
+
+
+ |
+
+
+ |
++ + | +
+ Mail delivery will be attempted to mail.example.com and
+ mail2.example.com (in
+ any order), and if neither of those succeed, delivery to mail.backup.org will
+ be attempted.
+
+ The time-to-live of the RR field is a 32-bit integer represented + in units of seconds, and is primarily used by resolvers when they + cache RRs. The TTL describes how long a RR can be cached before it + should be discarded. The following three types of TTL are + currently + used in a zone file. +
+|
+ + SOA + + |
+
+ + The last field in the SOA is the negative + caching TTL. This controls how long other servers will + cache no-such-domain + (NXDOMAIN) responses from you. + ++ The maximum time for + negative caching is 3 hours (3h). + + |
+
|
+ + $TTL + + |
+
+ + The $TTL directive at the top of the + zone file (before the SOA) gives a default TTL for every + RR without + a specific TTL set. + + |
+
|
+ + RR TTLs + + |
+
+ + Each RR can have a TTL as the second + field in the RR, which will control how long other + servers can cache it. + + |
+
+ All of these TTLs default to units of seconds, though units
+ can be explicitly specified, for example, 1h30m.
+
+ Reverse name resolution (that is, translation from IP address + to name) is achieved by means of the in-addr.arpa domain + and PTR records. Entries in the in-addr.arpa domain are made in + least-to-most significant order, read left to right. This is the + opposite order to the way IP addresses are usually written. Thus, + a machine with an IP address of 10.1.2.3 would have a + corresponding + in-addr.arpa name of + 3.2.1.10.in-addr.arpa. This name should have a PTR resource record + whose data field is the name of the machine or, optionally, + multiple + PTR records if the machine has more than one name. For example, + in the [example.com] domain: +
+|
+
+ |
+
+
+ |
+
|
+
+ |
+
+
+ |
+
+ The $ORIGIN lines in the examples + are for providing context to the examples only — they do not + necessarily + appear in the actual usage. They are only used here to indicate + that the example is relative to the listed origin. +
++ The Master File Format was initially defined in RFC 1035 and + has subsequently been extended. While the Master File Format + itself + is class independent all records in a Master File must be of the + same + class. +
++ Master File Directives include $ORIGIN, $INCLUDE, + and $TTL. +
+
+ When used in the label (or name) field, the asperand or
+ at-sign (@) symbol represents the current origin.
+ At the start of the zone file, it is the
+ <zone_name> (followed by
+ trailing dot).
+
+ Syntax: $ORIGIN
+ domain-name
+ [comment]
+
$ORIGIN
+ sets the domain name that will be appended to any
+ unqualified records. When a zone is first read in there
+ is an implicit $ORIGIN
+ <zone_name>.
+ (followed by trailing dot).
+ The current $ORIGIN is appended to
+ the domain specified in the $ORIGIN
+ argument if it is not absolute.
+
+$ORIGIN example.com. +WWW CNAME MAIN-SERVER ++ +
+ is equivalent to +
+ ++WWW.EXAMPLE.COM. CNAME MAIN-SERVER.EXAMPLE.COM. ++ +
+ Syntax: $INCLUDE
+ filename
+ [
+origin ]
+ [ comment ]
+
+ Read and process the file filename as
+ if it were included into the file at this point. If origin is
+ specified the file is processed with $ORIGIN set
+ to that value, otherwise the current $ORIGIN is
+ used.
+
+ The origin and the current domain name + revert to the values they had prior to the $INCLUDE once + the file has been read. +
++ RFC 1035 specifies that the current origin should be restored + after + an $INCLUDE, but it is silent + on whether the current + domain name should also be restored. BIND 9 restores both of + them. + This could be construed as a deviation from RFC 1035, a + feature, or both. +
+
+ Syntax: $GENERATE
+ range
+ lhs
+ [ttl]
+ [class]
+ type
+ rhs
+ [comment]
+
$GENERATE + is used to create a series of resource records that only + differ from each other by an + iterator. $GENERATE can be used to + easily generate the sets of records required to support + sub /24 reverse delegations described in RFC 2317: + Classless IN-ADDR.ARPA delegation. +
+ +$ORIGIN 0.0.192.IN-ADDR.ARPA. +$GENERATE 1-2 @ NS SERVER$.EXAMPLE. +$GENERATE 1-127 $ CNAME $.0+ +
+ is equivalent to +
+ +0.0.0.192.IN-ADDR.ARPA. NS SERVER1.EXAMPLE. +0.0.0.192.IN-ADDR.ARPA. NS SERVER2.EXAMPLE. +1.0.0.192.IN-ADDR.ARPA. CNAME 1.0.0.0.192.IN-ADDR.ARPA. +2.0.0.192.IN-ADDR.ARPA. CNAME 2.0.0.0.192.IN-ADDR.ARPA. +... +127.0.0.192.IN-ADDR.ARPA. CNAME 127.0.0.0.192.IN-ADDR.ARPA. ++ +
+ Generate a set of A and MX records. Note the MX's right hand + side is a quoted string. The quotes will be stripped when the + right hand side is processed. +
+ ++$ORIGIN EXAMPLE. +$GENERATE 1-127 HOST-$ A 1.2.3.$ +$GENERATE 1-127 HOST-$ MX "0 ."+ +
+ is equivalent to +
+ +HOST-1.EXAMPLE. A 1.2.3.1 +HOST-1.EXAMPLE. MX 0 . +HOST-2.EXAMPLE. A 1.2.3.2 +HOST-2.EXAMPLE. MX 0 . +HOST-3.EXAMPLE. A 1.2.3.3 +HOST-3.EXAMPLE. MX 0 . +... +HOST-127.EXAMPLE. A 1.2.3.127 +HOST-127.EXAMPLE. MX 0 . ++ +
|
+ range + |
+
+ + This can be one of two forms: start-stop + or start-stop/step. If the first form is used, then step + is set to 1. start, stop and step must be positive + integers between 0 and (2^31)-1. start must not be + larger than stop. + + |
+
|
+ lhs + |
+
+ This + describes the owner name of the resource records + to be created. Any single $ + (dollar sign) + symbols within the lhs string + are replaced by the iterator value. + + To get a $ in the output, you need to escape the + $ using a backslash + \, + e.g. \$. The + $ may optionally be followed + by modifiers which change the offset from the + iterator, field width and base. + + Modifiers are introduced by a + { (left brace) immediately following the + $ as + ${offset[,width[,base]]}. + For example, ${-20,3,d} + subtracts 20 from the current value, prints the + result as a decimal in a zero-padded field of + width 3. + + Available output forms are decimal + (d), octal + (o), hexadecimal + (x or X + for uppercase) and nibble + (n or N\ + for uppercase). The default modifier is + ${0,0,d}. If the + lhs is not absolute, the + current $ORIGIN is appended + to the name. + ++ In nibble mode the value will be treated as + if it was a reversed hexadecimal string + with each hexadecimal digit as a separate + label. The width field includes the label + separator. + ++ For compatibility with earlier versions, + $$ is still recognized as + indicating a literal $ in the output. + + |
+
|
+ ttl + |
+
+ + Specifies the time-to-live of the generated records. If + not specified this will be inherited using the + normal TTL inheritance rules. + +class + and ttl can be + entered in either order. + + |
+
|
+ class + |
+
+ + Specifies the class of the generated records. + This must match the zone class if it is + specified. + +class + and ttl can be + entered in either order. + + |
+
|
+ type + |
+
+ + Any valid type. + + |
+
|
+ rhs + |
+
+ + rhs, optionally, quoted string. + + |
+
+ The $GENERATE directive is a BIND extension + and not part of the standard zone file format. +
++ BIND 8 does not support the optional TTL and CLASS fields. +
++ In addition to the standard textual format, BIND 9 + supports the ability to read or dump to zone files in + other formats. +
+
+ The raw format is
+ a binary representation of zone data in a manner similar
+ to that used in zone transfers. Since it does not require
+ parsing text, load time is significantly reduced.
+
+ An even faster alternative is the map
+ format, which is an image of a BIND 9
+ in-memory zone database; it is capable of being loaded
+ directly into memory via the mmap()
+ function; the zone can begin serving queries almost
+ immediately.
+
+ For a primary server, a zone file in
+ raw or map
+ format is expected to be generated from a textual zone
+ file by the named-compilezone command.
+ For a secondary server or for a dynamic zone, it is automatically
+ generated (if this format is specified by the
+ masterfile-format option) when
+ named dumps the zone contents after
+ zone transfer or when applying prior updates.
+
+ If a zone file in a binary format needs manual modification, + it first must be converted to a textual form by the + named-compilezone command. All + necessary modification should go to the text file, which + should then be converted to the binary form by the + named-compilezone command again. +
+
+ Note that map format is extremely
+ architecture-specific. A map
+ file cannot be used on a system
+ with different pointer size, endianness or data alignment
+ than the system on which it was generated, and should in
+ general be used only inside a single system.
+ While raw format uses
+ network byte order and avoids architecture-dependent
+ data alignment so that it is as portable as
+ possible, it is also primarily expected to be used
+ inside the same single system. To export a
+ zone file in either raw or
+ map format, or make a
+ portable backup of such a file, conversion to
+ text format is recommended.
+
+ BIND 9 maintains lots of statistics + information and provides several interfaces for users to + get access to the statistics. + The available statistics include all statistics counters + that were available in BIND 8 and + are meaningful in BIND 9, + and other information that is considered useful. +
+ ++ The statistics information is categorized into the following + sections. +
+ +|
+ Incoming Requests + |
+
+ + The number of incoming DNS requests for each OPCODE. + + |
+
|
+ Incoming Queries + |
+
+ + The number of incoming queries for each RR type. + + |
+
|
+ Outgoing Queries + |
+
+ + The number of outgoing queries for each RR + type sent from the internal resolver. + Maintained per view. + + |
+
|
+ Name Server Statistics + |
+
+ + Statistics counters about incoming request processing. + + |
+
|
+ Zone Maintenance Statistics + |
+
+ + Statistics counters regarding zone maintenance + operations such as zone transfers. + + |
+
|
+ Resolver Statistics + |
+
+ + Statistics counters about name resolution + performed in the internal resolver. + Maintained per view. + + |
+
|
+ Cache DB RRsets + |
+
+ + The number of RRsets per RR type and nonexistent + names stored in the cache database. + If the exclamation mark (!) is printed for a RR + type, it means that particular type of RRset is + known to be nonexistent (this is also known as + "NXRRSET"). If a hash mark (#) is present then + the RRset is marked for garbage collection. + Maintained per view. + + |
+
|
+ Socket I/O Statistics + |
+
+ + Statistics counters about network related events. + + |
+
+ A subset of Name Server Statistics is collected and shown
+ per zone for which the server has the authority when
+ zone-statistics is set to
+ full (or yes
+ for backward compatibility. See the description of
+ zone-statistics in the section called “options Statement Definition and
+ Usage”
+ for further details.
+
+ These statistics counters are shown with their zone and + view names. The view name is omitted when the server is + not configured with explicit views.
+ ++ There are currently two user interfaces to get access to the + statistics. + One is in the plain text format dumped to the file specified + by the statistics-file configuration option. + The other is remotely accessible via a statistics channel + when the statistics-channels statement + is specified in the configuration file + (see the section called “statistics-channels Statement Grammar”.) +
+ ++ The text format statistics dump begins with a line, like: +
++ +++ Statistics Dump +++ (973798949) +
++ The number in parentheses is a standard + Unix-style timestamp, measured as seconds since January 1, 1970. + + Following + that line is a set of statistics information, which is categorized + as described above. + Each section begins with a line, like: +
+ ++ ++ Name Server Statistics ++ +
+ ++ Each section consists of lines, each containing the statistics + counter value followed by its textual description. + See below for available counters. + For brevity, counters that have a value of 0 are not shown + in the statistics file. +
+ ++ The statistics dump ends with the line where the + number is identical to the number in the beginning line; for example: +
++ --- Statistics Dump --- (973798949) +
++ The following tables summarize statistics counters that + BIND 9 provides. + For each row of the tables, the leftmost column is the + abbreviated symbol name of that counter. + These symbols are shown in the statistics information + accessed via an HTTP statistics channel. + The rightmost column gives the description of the counter, + which is also shown in the statistics file + (but, in this document, possibly with slight modification + for better readability). + Additional notes may also be provided in this column. + When a middle column exists between these two columns, + it gives the corresponding counter name of the + BIND 8 statistics, if applicable. +
+ +|
+ + Symbol + + |
+
+ + BIND8 Symbol + + |
+
+ + Description + + |
+
|
+ Requestv4 + |
+
+ RQ + |
+
+ + IPv4 requests received. + Note: this also counts non query requests. + + |
+
|
+ Requestv6 + |
+
+ RQ + |
+
+ + IPv6 requests received. + Note: this also counts non query requests. + + |
+
|
+ ReqEdns0 + |
+
+ + |
+
+ + Requests with EDNS(0) received. + + |
+
|
+ ReqBadEDNSVer + |
+
+ + |
+
+ + Requests with unsupported EDNS version received. + + |
+
|
+ ReqTSIG + |
+
+ + |
+
+ + Requests with TSIG received. + + |
+
|
+ ReqSIG0 + |
+
+ + |
+
+ + Requests with SIG(0) received. + + |
+
|
+ ReqBadSIG + |
+
+ + |
+
+ + Requests with invalid (TSIG or SIG(0)) signature. + + |
+
|
+ ReqTCP + |
+
+ RTCP + |
+
+ + TCP requests received. + + |
+
|
+ AuthQryRej + |
+
+ RUQ + |
+
+ + Authoritative (non recursive) queries rejected. + + |
+
|
+ RecQryRej + |
+
+ RURQ + |
+
+ + Recursive queries rejected. + + |
+
|
+ XfrRej + |
+
+ RUXFR + |
+
+ + Zone transfer requests rejected. + + |
+
|
+ UpdateRej + |
+
+ RUUpd + |
+
+ + Dynamic update requests rejected. + + |
+
|
+ Response + |
+
+ SAns + |
+
+ + Responses sent. + + |
+
|
+ RespTruncated + |
+
+ + |
+
+ + Truncated responses sent. + + |
+
|
+ RespEDNS0 + |
+
+ + |
+
+ + Responses with EDNS(0) sent. + + |
+
|
+ RespTSIG + |
+
+ + |
+
+ + Responses with TSIG sent. + + |
+
|
+ RespSIG0 + |
+
+ + |
+
+ + Responses with SIG(0) sent. + + |
+
|
+ QrySuccess + |
+
+ + |
+
+ + Queries resulted in a successful answer. + This means the query which returns a NOERROR response + with at least one answer RR. + This corresponds to the + success counter + of previous versions of + BIND 9. + + |
+
|
+ QryAuthAns + |
+
+ + |
+
+ + Queries resulted in authoritative answer. + + |
+
|
+ QryNoauthAns + |
+
+ SNaAns + |
+
+ + Queries resulted in non authoritative answer. + + |
+
|
+ QryReferral + |
+
+ + |
+
+ + Queries resulted in referral answer. + This corresponds to the + referral counter + of previous versions of + BIND 9. + + |
+
|
+ QryNxrrset + |
+
+ + |
+
+ + Queries resulted in NOERROR responses with no data. + This corresponds to the + nxrrset counter + of previous versions of + BIND 9. + + |
+
|
+ QrySERVFAIL + |
+
+ SFail + |
+
+ + Queries resulted in SERVFAIL. + + |
+
|
+ QryFORMERR + |
+
+ SFErr + |
+
+ + Queries resulted in FORMERR. + + |
+
|
+ QryNXDOMAIN + |
+
+ SNXD + |
+
+ + Queries resulted in NXDOMAIN. + This corresponds to the + nxdomain counter + of previous versions of + BIND 9. + + |
+
|
+ QryRecursion + |
+
+ RFwdQ + |
+
+ + Queries which caused the server + to perform recursion in order to find the final answer. + This corresponds to the + recursion counter + of previous versions of + BIND 9. + + |
+
|
+ QryDuplicate + |
+
+ RDupQ + |
+
+ + Queries which the server attempted to + recurse but discovered an existing query with the same + IP address, port, query ID, name, type and class + already being processed. + This corresponds to the + duplicate counter + of previous versions of + BIND 9. + + |
+
|
+ QryDropped + |
+
+ + |
+
+ + Recursive queries for which the server + discovered an excessive number of existing + recursive queries for the same name, type and + class and were subsequently dropped. + This is the number of dropped queries due to + the reason explained with the + clients-per-query + and + max-clients-per-query + options + (see the description about + clients-per-query.) + This corresponds to the + dropped counter + of previous versions of + BIND 9. + + |
+
|
+ QryFailure + |
+
+ + |
+
+ + Other query failures. + This corresponds to the + failure counter + of previous versions of + BIND 9. + Note: this counter is provided mainly for + backward compatibility with the previous versions. + Normally a more fine-grained counters such as + AuthQryRej and + RecQryRej + that would also fall into this counter are provided, + and so this counter would not be of much + interest in practice. + + |
+
|
+ QryNXRedir + |
+
+ + |
+
+ + Queries resulted in NXDOMAIN that were redirected. + + |
+
|
+ QryNXRedirRLookup + |
+
+ + |
+
+ + Queries resulted in NXDOMAIN that were redirected + and resulted in a successful remote lookup. + + |
+
|
+ XfrReqDone + |
+
+ + |
+
+ + Requested zone transfers completed. + + |
+
|
+ UpdateReqFwd + |
+
+ + |
+
+ + Update requests forwarded. + + |
+
|
+ UpdateRespFwd + |
+
+ + |
+
+ + Update responses forwarded. + + |
+
|
+ UpdateFwdFail + |
+
+ + |
+
+ + Dynamic update forward failed. + + |
+
|
+ UpdateDone + |
+
+ + |
+
+ + Dynamic updates completed. + + |
+
|
+ UpdateFail + |
+
+ + |
+
+ + Dynamic updates failed. + + |
+
|
+ UpdateBadPrereq + |
+
+ + |
+
+ + Dynamic updates rejected due to prerequisite failure. + + |
+
|
+ RateDropped + |
+
+ + |
+
+ + Responses dropped by rate limits. + + |
+
|
+ RateSlipped + |
+
+ + |
+
+ + Responses truncated by rate limits. + + |
+
|
+ RPZRewrites + |
+
+ + |
+
+ + Response policy zone rewrites. + + |
+
|
+ + Symbol + + |
+
+ + Description + + |
+
|
+ NotifyOutv4 + |
+
+ + IPv4 notifies sent. + + |
+
|
+ NotifyOutv6 + |
+
+ + IPv6 notifies sent. + + |
+
|
+ NotifyInv4 + |
+
+ + IPv4 notifies received. + + |
+
|
+ NotifyInv6 + |
+
+ + IPv6 notifies received. + + |
+
|
+ NotifyRej + |
+
+ + Incoming notifies rejected. + + |
+
|
+ SOAOutv4 + |
+
+ + IPv4 SOA queries sent. + + |
+
|
+ SOAOutv6 + |
+
+ + IPv6 SOA queries sent. + + |
+
|
+ AXFRReqv4 + |
+
+ + IPv4 AXFR requested. + + |
+
|
+ AXFRReqv6 + |
+
+ + IPv6 AXFR requested. + + |
+
|
+ IXFRReqv4 + |
+
+ + IPv4 IXFR requested. + + |
+
|
+ IXFRReqv6 + |
+
+ + IPv6 IXFR requested. + + |
+
|
+ XfrSuccess + |
+
+ + Zone transfer requests succeeded. + + |
+
|
+ XfrFail + |
+
+ + Zone transfer requests failed. + + |
+
|
+ + Symbol + + |
+
+ + BIND8 Symbol + + |
+
+ + Description + + |
+
|
+ Queryv4 + |
+
+ SFwdQ + |
+
+ + IPv4 queries sent. + + |
+
|
+ Queryv6 + |
+
+ SFwdQ + |
+
+ + IPv6 queries sent. + + |
+
|
+ Responsev4 + |
+
+ RR + |
+
+ + IPv4 responses received. + + |
+
|
+ Responsev6 + |
+
+ RR + |
+
+ + IPv6 responses received. + + |
+
|
+ NXDOMAIN + |
+
+ RNXD + |
+
+ + NXDOMAIN received. + + |
+
|
+ SERVFAIL + |
+
+ RFail + |
+
+ + SERVFAIL received. + + |
+
|
+ FORMERR + |
+
+ RFErr + |
+
+ + FORMERR received. + + |
+
|
+ OtherError + |
+
+ RErr + |
+
+ + Other errors received. + + |
+
|
+ EDNS0Fail + |
+
+ + |
+
+ + EDNS(0) query failures. + + |
+
|
+ Mismatch + |
+
+ RDupR + |
+
+ + Mismatch responses received. + The DNS ID, response's source address, + and/or the response's source port does not + match what was expected. + (The port must be 53 or as defined by + the port option.) + This may be an indication of a cache + poisoning attempt. + + |
+
|
+ Truncated + |
+
+ + |
+
+ + Truncated responses received. + + |
+
|
+ Lame + |
+
+ RLame + |
+
+ + Lame delegations received. + + |
+
|
+ Retry + |
+
+ SDupQ + |
+
+ + Query retries performed. + + |
+
|
+ QueryAbort + |
+
+ + |
+
+ + Queries aborted due to quota control. + + |
+
|
+ QuerySockFail + |
+
+ + |
+
+ + Failures in opening query sockets. + One common reason for such failures is a + failure of opening a new socket due to a + limitation on file descriptors. + + |
+
|
+ QueryTimeout + |
+
+ + |
+
+ + Query timeouts. + + |
+
|
+ GlueFetchv4 + |
+
+ SSysQ + |
+
+ + IPv4 NS address fetches invoked. + + |
+
|
+ GlueFetchv6 + |
+
+ SSysQ + |
+
+ + IPv6 NS address fetches invoked. + + |
+
|
+ GlueFetchv4Fail + |
+
+ + |
+
+ + IPv4 NS address fetch failed. + + |
+
|
+ GlueFetchv6Fail + |
+
+ + |
+
+ + IPv6 NS address fetch failed. + + |
+
|
+ ValAttempt + |
+
+ + |
+
+ + DNSSEC validation attempted. + + |
+
|
+ ValOk + |
+
+ + |
+
+ + DNSSEC validation succeeded. + + |
+
|
+ ValNegOk + |
+
+ + |
+
+ + DNSSEC validation on negative information succeeded. + + |
+
|
+ ValFail + |
+
+ + |
+
+ + DNSSEC validation failed. + + |
+
|
+ QryRTTnn + |
+
+ + |
+
+ + Frequency table on round trip times (RTTs) of + queries. + Each nn specifies the corresponding + frequency. + In the sequence of + nn_1, + nn_2, + ..., + nn_m, + the value of nn_i is the + number of queries whose RTTs are between + nn_(i-1) (inclusive) and + nn_i (exclusive) milliseconds. + For the sake of convenience we define + nn_0 to be 0. + The last entry should be represented as + nn_m+, which means the + number of queries whose RTTs are equal to or over + nn_m milliseconds. + + |
+
+ Socket I/O statistics counters are defined per socket + types, which are + UDP4 (UDP/IPv4), + UDP6 (UDP/IPv6), + TCP4 (TCP/IPv4), + TCP6 (TCP/IPv6), + Unix (Unix Domain), and + FDwatch (sockets opened outside the + socket module). + In the following table <TYPE> + represents a socket type. + Not all counters are available for all socket types; + exceptions are noted in the description field. +
+ +|
+ + Symbol + + |
+
+ + Description + + |
+
|
+ <TYPE>Open + |
+
+ + Sockets opened successfully. + This counter is not applicable to the + FDwatch type. + + |
+
|
+ <TYPE>OpenFail + |
+
+ + Failures of opening sockets. + This counter is not applicable to the + FDwatch type. + + |
+
|
+ <TYPE>Close + |
+
+ + Sockets closed. + + |
+
|
+ <TYPE>BindFail + |
+
+ + Failures of binding sockets. + + |
+
|
+ <TYPE>ConnFail + |
+
+ + Failures of connecting sockets. + + |
+
|
+ <TYPE>Conn + |
+
+ + Connections established successfully. + + |
+
|
+ <TYPE>AcceptFail + |
+
+ + Failures of accepting incoming connection requests. + This counter is not applicable to the + UDP and + FDwatch types. + + |
+
|
+ <TYPE>Accept + |
+
+ + Incoming connections successfully accepted. + This counter is not applicable to the + UDP and + FDwatch types. + + |
+
|
+ <TYPE>SendErr + |
+
+ + Errors in socket send operations. + This counter corresponds + to SErr counter of + BIND 8. + + |
+
|
+ <TYPE>RecvErr + |
+
+ + Errors in socket receive operations. + This includes errors of send operations on a + connected UDP socket notified by an ICMP error + message. + + |
+
+ Most statistics counters that were available + in BIND 8 are also supported in + BIND 9 as shown in the above tables. + Here are notes about other counters that do not appear + in these tables. +
+ ++ These counters are not supported + because BIND 9 does not adopt + the notion of forwarding + as BIND 8 did. +
++ This counter is accessible in the Incoming Queries section. +
++ This counter is accessible in the Incoming Requests section. +
++ This counter is not supported + because BIND 9 does not care + about IP options in the first place. +
+BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch07.html b/doc/arm/Bv9ARM.ch07.html new file mode 100644 index 0000000000000000000000000000000000000000..e079a93d604d4b7000cf9260f02071bdb684f4a2 --- /dev/null +++ b/doc/arm/Bv9ARM.ch07.html @@ -0,0 +1,404 @@ + + + + + +Table of Contents
+ ++ Access Control Lists (ACLs) are address match lists that + you can set up and nickname for future use in + allow-notify, allow-query, + allow-query-on, allow-recursion, + blackhole, allow-transfer, + match-clients, etc. +
++ Using ACLs allows you to have finer control over who can access + your name server, without cluttering up your config files with huge + lists of IP addresses. +
++ It is a good idea to use ACLs, and to + control access to your server. Limiting access to your server by + outside parties can help prevent spoofing and denial of service + (DoS) attacks against your server. +
++ ACLs match clients on the basis of up to three characteristics: + 1) The client's IP address; 2) the TSIG or SIG(0) key that was + used to sign the request, if any; and 3) an address prefix + encoded in an EDNS Client Subnet option, if any. +
++ Here is an example of ACLs based on client addresses: +
+ +
+// Set up an ACL named "bogusnets" that will block
+// RFC1918 space and some reserved space, which is
+// commonly used in spoofing attacks.
+acl bogusnets {
+ 0.0.0.0/8; 192.0.2.0/24; 224.0.0.0/3;
+ 10.0.0.0/8; 172.16.0.0/12; 192.168.0.0/16;
+};
+
+// Set up an ACL called our-nets. Replace this with the
+// real IP numbers.
+acl our-nets { x.x.x.x/24; x.x.x.x/21; };
+options {
+ ...
+ ...
+ allow-query { our-nets; };
+ allow-recursion { our-nets; };
+ ...
+ blackhole { bogusnets; };
+ ...
+};
+
+zone "example.com" {
+ type master;
+ file "m/example.com";
+ allow-query { any; };
+};
+
+
+ + This allows authoritative queries for "example.com" from any + address, but recursive queries only from the networks specified + in "our-nets", and no queries at all from the networks + specified in "bogusnets". +
+
+ In addition to network addresses and prefixes, which are
+ matched against the source address of the DNS request, ACLs
+ may include key elements, which specify the
+ name of a TSIG or SIG(0) key, or ecs
+ elements, which specify a network prefix but are only matched
+ if that prefix matches an EDNS client subnet option included
+ in the request.
+
+ The EDNS Client Subnet (ECS) option is used by a recursive
+ resolver to inform an authoritative name server of the network
+ address block from which the original query was received, enabling
+ authoritative servers to give different answers to the same
+ resolver for different resolver clients. An ACL containing
+ an element of the form
+ ecs prefix
+ will match if a request arrives in containing an ECS option
+ encoding an address within that prefix. If the request has no
+ ECS option, then "ecs" elements are simply ignored. Addresses
+ in ACLs that are not prefixed with "ecs" are matched only
+ against the source address.
+
+ (Note: The authoritative ECS implementation in + named is based on an early version of the + specification, and is known to have incompatibilities with + other implementations. It is also inefficient, requiring + a separate view for each client subnet to be sent different + answers, and it is unable to correct for overlapping subnets in + the configuration. It can be used for testing purposes, but is + not recommended for production use.) +
+
+ When BIND 9 is built with GeoIP support,
+ ACLs can also be used for geographic access restrictions.
+ This is done by specifying an ACL element of the form:
+ geoip [db database] field value
+
+ The field indicates which field
+ to search for a match. Available fields are "country",
+ "region", "city", "continent", "postal" (postal code),
+ "metro" (metro code), "area" (area code), "tz" (timezone),
+ "isp", "org", "asnum", "domain" and "netspeed".
+
+ value is the value to search
+ for within the database. A string may be quoted if it
+ contains spaces or other special characters. If this is
+ an "asnum" search, then the leading "ASNNNN" string can be
+ used, otherwise the full description must be used (e.g.
+ "ASNNNN Example Company Name"). If this is a "country"
+ search and the string is two characters long, then it must
+ be a standard ISO-3166-1 two-letter country code, and if it
+ is three characters long then it must be an ISO-3166-1
+ three-letter country code; otherwise it is the full name
+ of the country. Similarly, if this is a "region" search
+ and the string is two characters long, then it must be a
+ standard two-letter state or province abbreviation;
+ otherwise it is the full name of the state or province.
+
+ The database field indicates which
+ GeoIP database to search for a match. In most cases this is
+ unnecessary, because most search fields can only be found in
+ a single database. However, searches for country can be
+ answered from the "city", "region", or "country" databases,
+ and searches for region (i.e., state or province) can be
+ answered from the "city" or "region" databases. For these
+ search types, specifying a database
+ will force the query to be answered from that database and no
+ other. If database is not
+ specified, then these queries will be answered from the "city",
+ database if it is installed, or the "region" database if it is
+ installed, or the "country" database, in that order.
+
+ By default, if a DNS query includes an EDNS Client Subnet (ECS)
+ option which encodes a non-zero address prefix, then GeoIP ACLs
+ will be matched against that address prefix. Otherwise, they
+ are matched against the source address of the query. To
+ prevent GeoIP ACLs from matching against ECS options, set
+ the geoip-use-ecs to no.
+
+ Some example GeoIP ACLs: +
+geoip country US; +geoip country JAP; +geoip db country country Canada; +geoip db region region WA; +geoip city "San Francisco"; +geoip region Oklahoma; +geoip postal 95062; +geoip tz "America/Los_Angeles"; +geoip org "Internet Systems Consortium"; ++ +
+ ACLs use a "first-match" logic rather than "best-match": + if an address prefix matches an ACL element, then that ACL + is considered to have matched even if a later element would + have matched more specifically. For example, the ACL + { 10/8; !10.0.0.1; } would actually + match a query from 10.0.0.1, because the first element + indicated that the query should be accepted, and the second + element is ignored. +
++ When using "nested" ACLs (that is, ACLs included or referenced + within other ACLs), a negative match of a nested ACL will + the containing ACL to continue looking for matches. This + enables complex ACLs to be constructed, in which multiple + client characteristics can be checked at the same time. For + example, to construct an ACL which allows queries only when + it originates from a particular network and + only when it is signed with a particular key, use: +
+
+allow-query { !{ !10/8; any; }; key example; };
+
+ + Within the nested ACL, any address that is + not in the 10/8 network prefix will + be rejected, and this will terminate processing of the + ACL. Any address that is in the 10/8 + network prefix will be accepted, but this causes a negative + match of the nested ACL, so the containing ACL continues + processing. The query will then be accepted if it is signed + by the key "example", and rejected otherwise. The ACL, then, + will only matches when both conditions + are true. +
+
+ On UNIX servers, it is possible to run BIND
+ in a chrooted environment (using
+ the chroot() function) by specifying
+ the -t option for named.
+ This can help improve system security by placing
+ BIND in a "sandbox", which will limit
+ the damage done if a server is compromised.
+
+ Another useful feature in the UNIX version of BIND is the
+ ability to run the daemon as an unprivileged user ( -u user ).
+ We suggest running as an unprivileged user when using the chroot feature.
+
+ Here is an example command line to load BIND in a chroot sandbox, + /var/named, and to run named setuid to + user 202: +
+
+ /usr/local/sbin/named -u 202 -t /var/named
+
+ In order for a chroot environment
+ to work properly in a particular directory (for example,
+ /var/named), you will need to set
+ up an environment that includes everything
+ BIND needs to run. From
+ BIND's point of view,
+ /var/named is the root of the
+ filesystem. You will need to adjust the values of
+ options like directory and
+ pid-file to account for this.
+
+ Unlike with earlier versions of BIND, you typically will
+ not need to compile named
+ statically nor install shared libraries under the new root.
+ However, depending on your operating system, you may need
+ to set up things like
+ /dev/zero,
+ /dev/random,
+ /dev/log, and
+ /etc/localtime.
+
+ Prior to running the named daemon, + use + the touch utility (to change file + access and + modification times) or the chown + utility (to + set the user id and/or group id) on files + to which you want BIND + to write. +
++ If the named daemon is running as an + unprivileged user, it will not be able to bind to new restricted + ports if the server is reloaded. +
++ Access to the dynamic + update facility should be strictly limited. In earlier versions of + BIND, the only way to do this was + based on the IP + address of the host requesting the update, by listing an IP address + or + network prefix in the allow-update + zone option. + This method is insecure since the source address of the update UDP + packet + is easily forged. Also note that if the IP addresses allowed by the + allow-update option include the + address of a slave + server which performs forwarding of dynamic updates, the master can + be + trivially attacked by sending the update to the slave, which will + forward it to the master with its own source IP address causing the + master to approve it without question. +
+ ++ For these reasons, we strongly recommend that updates be + cryptographically authenticated by means of transaction signatures + (TSIG). That is, the allow-update + option should + list only TSIG key names, not IP addresses or network + prefixes. Alternatively, the new update-policy + option can be used. +
+ ++ Some sites choose to keep all dynamically-updated DNS data + in a subdomain and delegate that subdomain to a separate zone. This + way, the top-level zone containing critical data such as the IP + addresses + of public web and mail servers need not allow dynamic update at + all. +
+ +BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch08.html b/doc/arm/Bv9ARM.ch08.html new file mode 100644 index 0000000000000000000000000000000000000000..f9071bb69e52ca968e090d7dcbd27d709447d7ce --- /dev/null +++ b/doc/arm/Bv9ARM.ch08.html @@ -0,0 +1,141 @@ + + + + + +Table of Contents
+ ++ The best solution to solving installation and + configuration issues is to take preventative measures by setting + up logging files beforehand. The log files provide a + source of hints and information that can be used to figure out + what went wrong and how to fix the problem. +
+ ++ Zone serial numbers are just numbers — they aren't + date related. A lot of people set them to a number that + represents a date, usually of the form YYYYMMDDRR. + Occasionally they will make a mistake and set them to a + "date in the future" then try to correct them by setting + them to the "current date". This causes problems because + serial numbers are used to indicate that a zone has been + updated. If the serial number on the slave server is + lower than the serial number on the master, the slave + server will attempt to update its copy of the zone. +
+ ++ Setting the serial number to a lower number on the master + server than the slave server means that the slave will not perform + updates to its copy of the zone. +
+ ++ The solution to this is to add 2147483647 (2^31-1) to the + number, reload the zone and make sure all slaves have updated to + the new zone serial number, then reset the number to what you want + it to be, and reload the zone again. +
+ ++ The Internet Systems Consortium + (ISC) offers a wide range + of support and service agreements for BIND and DHCP servers. Four + levels of premium support are available and each level includes + support for all ISC programs, + significant discounts on products + and training, and a recognized priority on bug fixes and + non-funded feature requests. In addition, ISC offers a standard + support agreement package which includes services ranging from bug + fix announcements to remote support. It also includes training in + BIND and DHCP. +
+ ++ To discuss arrangements for support, contact + info@isc.org or visit the + ISC web page at + http://www.isc.org/services/support/ + to read more. +
+BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch09.html b/doc/arm/Bv9ARM.ch09.html new file mode 100644 index 0000000000000000000000000000000000000000..093e911cc8f79ed40ef1d004d56ab4722db73c11 --- /dev/null +++ b/doc/arm/Bv9ARM.ch09.html @@ -0,0 +1,586 @@ + + + + + +Table of Contents
+ ++ BIND 9.12.0 is a new feature release of BIND, still under development. + This document summarizes new features and functional changes that + have been introduced on this branch. With each development + release leading up to the final BIND 9.12.0 release, this document + will be updated with additional features added and bugs fixed. +
++ The latest versions of BIND 9 software can always be found at + http://www.isc.org/downloads/. + There you will find additional information about each release, + source code, and pre-compiled versions for Microsoft Windows + operating systems. +
++ With the release of BIND 9.11.0, ISC changed to the open + source license for BIND from the ISC license to the Mozilla + Public License (MPL 2.0). +
++ The MPL-2.0 license requires that if you make changes to + licensed software (e.g. BIND) and distribute them outside + your organization, that you publish those changes under that + same license. It does not require that you publish or disclose + anything other than the changes you made to our software. +
++ This requirement will not affect anyone who is using BIND + without redistributing it, nor anyone redistributing it without + changes, therefore this change will be without consequence + for most individuals and organizations who are using BIND. +
++ Those unsure whether or not the license change affects their + use of BIND, or who wish to discuss how to comply with the + license may contact ISC at + https://www.isc.org/mission/contact/. +
++ As of BIND 9.11.2, Windows XP is no longer a supported platform for + BIND, and Windows XP binaries are no longer available for download + from ISC. +
++ Many aspects of named have been modified + to improve query performance, and in particular, performance + for delegation-heavy zones: +
++ The additional cache ("acache") was found not to + significantly improve performance and has been removed; + the acache-enable and + acache-cleaning-interval options are now + deprecated. +
++ In place of the acache, named can now use + a glue cache to speed up retrieval of glue records when sending + delegation responses. Unlike acache, this feature is on by + default; use glue-cache no; to disable it. +
++ The additional-from-cache + and additional-from-auth options have been + deprecated. +
+
+ minimal-responses is now set
+ to yes by default.
+
+ Several functions have been refactored to improve + performance, including name compression, owner name + case restoration, hashing, and buffers. +
++ Several areas of code have been refactored for improved + readability, maintainability, and testability: +
++ The named query logic implemented in + query_find() has been split into + smaller functions with a context structure to maintain state + between them, and extensive comments have been added. + [RT #43929] +
++ Similarly the iterative query logic implemented in + resquery_response() function has been + split into smaller functions and comments added. [RT #45362] +
++ Code implementing name server query processing has been moved + from named to an external library, + libns. This will make it easier to + write unit tests for the code, or to link it into new tools. + [RT #45186] +
++ named can now synthesize NXDOMAIN responses + from cached DNSSEC-verified records returned in negative or + wildcard responses. This will reduce query loads on + authoritative servers for signed domains: if existing cached + records can be used by the resolver to determine that a name does + not exist in the authorittive domain, then no query needs to + be sent. +
+
+ This behavior is controlled by the new
+ named.conf option
+ synth-from-dnssec. It is enabled by
+ default.
+
+ Note: This initial implementation can only synthesize NXDOMAIN + responses, from NSEC records. Support for NODATA responses, + wilcard responses, and NSEC3 records will be added soon. +
++ The DNS Response Policy Service (DNSRPS) API, a mechanism to + allow named to use an external response policy + provider, is now supported. (One example of such a provider is + "FastRPZ" from Farsight Security, Inc.) This allows the same + types of policy filtering as standard RPZ, but can reduce the + workload for named, particularly when using + large and frequently-updated policy zones. It also enables + named to share response policy providers + with other DNS implementations such as Unbound. +
+
+ This feature is avaiable if BIND is built with
+ configure --enable-dnsrps, if a DNSRPS
+ provider is installed, and if dnsrps-enable
+ is set to "yes" in named.conf. Standard
+ built-in RPZ is used otherwise.
+
+ Thanks to Vernon Schryver and Farsight Security for the + contribution. [RT #43376] +
+
+ Setting max-journal-size to
+ default limits journal sizes to twice the
+ size of the zone contents. This can be overridden by setting
+ max-journal-size to unlimited
+ or to an explicit value up to 2G. Thanks to Tony Finch for
+ the contribution. [RT #38324]
+
+ dnstap logfiles can now be configured to
+ automatically roll when they reach a specified size. If
+ dnstap-output is configured with mode
+ file, then it can take optional
+ size and versions
+ key-value arguments to set the logfile rolling parameters.
+ (These have the same semantics as the corresponding
+ options in a logging channel statement.)
+ [RT #44502]
+
+ Logging channels and dnstap-output files can
+ now be configured with a suffix option,
+ set to either increment or
+ timestamp, indicating whether log files
+ should be given incrementing suffixes when they roll
+ over (e.g., logfile.0,
+ .1, .2, etc)
+ or suffixes indicating the time of the roll. The default
+ is increment. [RT #42838]
+
+ The print-time option in the
+ logging configuration can now take arguments
+ local, iso8601 or
+ iso8601-utc to indicate the format in
+ which the date and time should be logged. For backward
+ compatibility, yes is a synonym for
+ local. [RT #42585]
+
+ nsupdate and rndc now accepts + command line options -4 and -6 + which force using only IPv4 or only IPv6, respectively. [RT #45632] +
++ nsec3hash -r ("rdata order") takes arguments + in the same order as they appear in NSEC3 or NSEC3PARAM records. + This makes it easier to generate an NSEC3 hash using values cut + and pasted from an existing record. Thanks to Tony Finch for + the contribution. [RT #45183] +
++ The new-zones-directory option allows + named to store configuration parameters + for zones added via rndc addzone in a + location other than the working directory. Thanks to Petr + Menšík of Red Hat for the contribution. + [RT #44853] +
++ The dnstap-read -x option prints a hex + dump of the wire format DNS message encapsulated in each + dnstap log entry. [RT #44816] +
++ The host -A option returns most + records for a name, but omits types RRSIG, NSEC and NSEC3. +
++ dig +ednsopt now accepts the names + for EDNS options in addition to numeric values. For example, + an EDNS Client-Subnet option could be sent using + dig +ednsopt=ecs:.... Thanks to + John Worley of Secure64 for the contribution. [RT #44461] +
++ Added support for the EDNS TCP Keepalive option (RFC 7828); + this allows negotiation of longer-lived TCP sessions + to reduce the overhead of setting up TCP for individual + queries. [RT #42126] +
++ Added support for the EDNS Padding option (RFC 7830), + which obfuscates packet size analysis when DNS queries + are sent over an encrypted channel. [RT #42094] +
++ rndc commands which refer to zone names + can now reference a zone of type redirect + by using the special zone name "-redirect". (Previously this + was not possible because redirect zones + always have the name ".", which can be ambiguous.) +
++ In the event you need to manipulate a zone actually + called "-redirect", use a trailing dot: "-redirect." +
++ Note: This change does not appply to the + rndc addzone or + rndc modzone commands. +
+
+ named-checkconf -l lists the zones found
+ in named.conf. [RT #43154]
+
+ Query logging now includes the ECS option, if one was
+ present in the query, in the format
+ "[ECS address/source/scope]".
+
+ BIND can now use the Ed25519 and Ed448 Edwards Curve DNSSEC + signing algorithms described in RFC 8080. Note, however, that + these algorithms must be supported in OpenSSL; + currently they are only available in the development branch + of OpenSSL at + https://github.com/openssl/openssl. + [RT #44696] +
++ EDNS KEY TAG options are verified and printed. +
++ The lightweight resolver daemon and library (lwresd + and liblwres) have been removed. [RT #45186] +
+
+ dnssec-keygen no longer has default
+ algorithm settings. It is necessary to explicitly specify the
+ algorithm on the command line with the -a option
+ when generating keys. This may cause errors with existing signing
+ scripts if they rely on current defaults. The intent is to
+ reduce the long-term cost of transitioning to newer algorithms in
+ the event of RSASHA1 being deprecated. [RT #44755]
+
+ dig +sigchase and related options + +trusted-keys and +topdown + have been removed. delv is now the recommended + command for looking up records with DNSSEC validation. + [RT #42793] +
++ The Response Policy Zone (RPZ) implementation has been + substantially refactored: updates to the RPZ summary + database are no longer directly performed by the zone + database but by a separate function that is called when + a policy zone is updated. This improves both performance + and reliability when policy zones receive frequent updates. + Summary database updates can be rate-limited by using the + min-update-interval option in a + response-policy statement. [RT #43449] +
++ dnstap now stores both the local and remote + addresses for all messages, instead of only the remote address. + The default output format for dnstap-read has + been updated to include these addresses, with the initiating + address first and the responding address second, separated by + "-%gt;" or "%lt;-" to indicate in which direction the message + was sent. [RT #43595] +
++ Expanded and improved the YAML output from + dnstap-read -y: it now includes packet + size and a detailed breakdown of message contents. + [RT #43622] [RT #43642] +
++ Threads in named are now set to human-readable + names to assist debugging on operating systems that support that. + Threads will have names such as "isc-timer", "isc-sockmgr", + "isc-worker0001", and so on. This will affect the reporting of + subsidiary thread names in ps and + top, but not the main thread. [RT #43234] +
++ If an ACL is specified with an address prefix in which the + prefix length is longer than the address portion (for example, + 192.0.2.1/8), it will now be treated as a fatal error during + configuration. [RT #43367] +
++ dig now warns about .local queries which are + reserved for Multicast DNS. [RT #44783] +
++ The view associated with the query is now logged unless it + it is "_default/IN" or "_dnsclient/IN" when logging DNSSEC + validator messages. +
+
+ Multiple cookie-secret clauses are now
+ supported. The first cookie-secret in
+ named.conf is used to generate new
+ server cookies. Any others are used to accept old server
+ cookies or those generated by other servers using the
+ matching cookie-secret.
+
+ The end of life for BIND 9.12 is yet to be determined but + will not be before BIND 9.14.0 has been released for 6 months. + https://www.isc.org/downloads/software-support-policy/ +
++ Thank you to everyone who assisted us in making this release possible. + If you would like to contribute to ISC to assist us in continuing to + make quality open source software, please visit our donations page at + http://www.isc.org/donate/. +
+BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch10.html b/doc/arm/Bv9ARM.ch10.html new file mode 100644 index 0000000000000000000000000000000000000000..61465c213dae77fee38306790a471f558da45364 --- /dev/null +++ b/doc/arm/Bv9ARM.ch10.html @@ -0,0 +1,153 @@ + + + + + ++ Although the "official" beginning of the Domain Name + System occurred in 1984 with the publication of RFC 920, the + core of the new system was described in 1983 in RFCs 882 and + 883. From 1984 to 1987, the ARPAnet (the precursor to today's + Internet) became a testbed of experimentation for developing the + new naming/addressing scheme in a rapidly expanding, + operational network environment. New RFCs were written and + published in 1987 that modified the original documents to + incorporate improvements based on the working model. RFC 1034, + "Domain Names-Concepts and Facilities", and RFC 1035, "Domain + Names-Implementation and Specification" were published and + became the standards upon which all DNS implementations are + built. +
+ ++ The first working domain name server, called "Jeeves", was + written in 1983-84 by Paul Mockapetris for operation on DEC + Tops-20 + machines located at the University of Southern California's + Information + Sciences Institute (USC-ISI) and SRI International's Network + Information + Center (SRI-NIC). A DNS server for + Unix machines, the Berkeley Internet + Name Domain (BIND) package, was + written soon after by a group of + graduate students at the University of California at Berkeley + under + a grant from the US Defense Advanced Research Projects + Administration + (DARPA). +
++ Versions of BIND through + 4.8.3 were maintained by the Computer + Systems Research Group (CSRG) at UC Berkeley. Douglas Terry, Mark + Painter, David Riggle and Songnian Zhou made up the initial BIND + project team. After that, additional work on the software package + was done by Ralph Campbell. Kevin Dunlap, a Digital Equipment + Corporation + employee on loan to the CSRG, worked on BIND for 2 years, from 1985 + to 1987. Many other people also contributed to BIND development + during that time: Doug Kingston, Craig Partridge, Smoot + Carl-Mitchell, + Mike Muuss, Jim Bloom and Mike Schwartz. BIND maintenance was subsequently + handled by Mike Karels and Øivind Kure. +
++ BIND versions 4.9 and 4.9.1 were + released by Digital Equipment + Corporation (now Compaq Computer Corporation). Paul Vixie, then + a DEC employee, became BIND's + primary caretaker. He was assisted + by Phil Almquist, Robert Elz, Alan Barrett, Paul Albitz, Bryan + Beecher, Andrew + Partan, Andy Cherenson, Tom Limoncelli, Berthold Paffrath, Fuat + Baran, Anant Kumar, Art Harkin, Win Treese, Don Lewis, Christophe + Wolfhugel, and others. +
++ In 1994, BIND version 4.9.2 was sponsored by + Vixie Enterprises. Paul + Vixie became BIND's principal + architect/programmer. +
++ BIND versions from 4.9.3 onward + have been developed and maintained + by the Internet Systems Consortium and its predecessor, + the Internet Software Consortium, with support being provided + by ISC's sponsors. +
++ As co-architects/programmers, Bob Halley and + Paul Vixie released the first production-ready version of + BIND version 8 in May 1997. +
++ BIND version 9 was released in September 2000 and is a + major rewrite of nearly all aspects of the underlying + BIND architecture. +
++ BIND versions 4 and 8 are officially deprecated. + No additional development is done + on BIND version 4 or BIND version 8. +
++ BIND development work is made + possible today by the sponsorship + of several corporations, and by the tireless work efforts of + numerous individuals. +
+BIND 9.12.0-pre-alpha
+ + diff --git a/doc/arm/Bv9ARM.ch11.html b/doc/arm/Bv9ARM.ch11.html new file mode 100644 index 0000000000000000000000000000000000000000..a3ff9d135a6dda36cf29db5662cae775e0bbfed5 --- /dev/null +++ b/doc/arm/Bv9ARM.ch11.html @@ -0,0 +1,919 @@ + + + + + +Table of Contents
+ ++ IPv6 addresses are 128-bit identifiers for interfaces and + sets of interfaces which were introduced in the DNS to facilitate + scalable Internet routing. There are three types of addresses: Unicast, + an identifier for a single interface; + Anycast, + an identifier for a set of interfaces; and Multicast, + an identifier for a set of interfaces. Here we describe the global + Unicast address scheme. For more information, see RFC 3587, + "Global Unicast Address Format." +
++ IPv6 unicast addresses consist of a + global routing prefix, a + subnet identifier, and an + interface identifier. +
++ The global routing prefix is provided by the + upstream provider or ISP, and (roughly) corresponds to the + IPv4 network section + of the address range. + + The subnet identifier is for local subnetting, much the + same as subnetting an + IPv4 /16 network into /24 subnets. + + The interface identifier is the address of an individual + interface on a given network; in IPv6, addresses belong to + interfaces rather than to machines. +
++ The subnetting capability of IPv6 is much more flexible than + that of IPv4: subnetting can be carried out on bit boundaries, + in much the same way as Classless InterDomain Routing + (CIDR), and the DNS PTR representation ("nibble" format) + makes setting up reverse zones easier. +
++ The Interface Identifier must be unique on the local link, + and is usually generated automatically by the IPv6 + implementation, although it is usually possible to + override the default setting if necessary. A typical IPv6 + address might look like: + 2001:db8:201:9:a00:20ff:fe81:2b32 +
++ IPv6 address specifications often contain long strings + of zeros, so the architects have included a shorthand for + specifying + them. The double colon (`::') indicates the longest possible + string + of zeros that can fit, and can be used only once in an address. +
++ Specification documents for the Internet protocol suite, including + the DNS, are published as part of + the Request for Comments (RFCs) + series of technical notes. The standards themselves are defined + by the Internet Engineering Task Force (IETF) and the Internet + Engineering Steering Group (IESG). RFCs can be obtained online via FTP at: +
+
+
+ ftp://www.isi.edu/in-notes/RFCxxxx.txt
+
+
+ (where xxxx is
+ the number of the RFC). RFCs are also available via the Web at:
+
[RFC2168] + + + Resolution of Uniform Resource Identifiers using + the Domain Name System. + June 1997. +
+[RFC1876] + + + A Means for Expressing Location Information in the + Domain + Name System. + January 1996. +
+[RFC2163] + + + Using the Internet DNS to + Distribute MIXER + Conformant Global Address Mapping. + January 1998. +
+[RFC2825] + + + A Tangled Web: Issues of I18N, Domain Names, + and the Other Internet protocols. + May 2000. +
++ Note: the following list of RFCs, although + DNS-related, are not + concerned with implementing software. +
+[RFC1464] + + + Using the Domain Name System To Store Arbitrary String + Attributes. + May 1993. +
++ Most of these have been consolidated into RFC4033, + RFC4034 and RFC4035 which collectively describe DNSSECbis. +
+