dnssec-signzone — DNSSEC zone signing tool


dnssec-signzone [-a] [-c class] [-d directory] [-e end-time] [-f output-file] [-g] [-h] [-k key] [-l domain] [-i interval] [-I input-format] [-j jitter] [-n nthreads] [-o origin] [-O output-format] [-p] [-r randomdev] [-s start-time] [-t] [-v level] [-z] {zonefile} [key...]


dnssec-signzone signs a zone. It generates NSEC and RRSIG records and produces a signed version of the zone. The security status of delegations from the signed zone (that is, whether the child zones are secure or not) is determined by the presence or absence of a keyset file for each child zone.



Verify all generated signatures.

-c class

Specifies the DNS class of the zone.

-k key

Treat specified key as a key signing key ignoring any key flags. This option may be specified multiple times.

-l domain

Generate a DLV set in addition to the key (DNSKEY) and DS sets. The domain is appended to the name of the records.

-d directory

Look for keyset files in directory as the directory


Generate DS records for child zones from keyset files. Existing DS records will be removed.

-s start-time

Specify the date and time when the generated RRSIG records become valid. This can be either an absolute or relative time. An absolute start time is indicated by a number in YYYYMMDDHHMMSS notation; 20000530144500 denotes 14:45:00 UTC on May 30th, 2000. A relative start time is indicated by +N, which is N seconds from the current time. If no start-time is specified, the current time minus 1 hour (to allow for clock skew) is used.

-e end-time

Specify the date and time when the generated RRSIG records expire. As with start-time, an absolute time is indicated in YYYYMMDDHHMMSS notation. A time relative to the start time is indicated with +N, which is N seconds from the start time. A time relative to the current time is indicated with now+N. If no end-time is specified, 30 days from the start time is used as a default.

-f output-file

The name of the output file containing the signed zone. The default is to append .signed to the input file.


Prints a short summary of the options and arguments to dnssec-signzone.

-i interval

When a previously signed zone is passed as input, records may be resigned. The interval option specifies the cycle interval as an offset from the current time (in seconds). If a RRSIG record expires after the cycle interval, it is retained. Otherwise, it is considered to be expiring soon, and it will be replaced.

The default cycle interval is one quarter of the difference between the signature end and start times. So if neither end-time or start-time are specified, dnssec-signzone generates signatures that are valid for 30 days, with a cycle interval of 7.5 days. Therefore, if any existing RRSIG records are due to expire in less than 7.5 days, they would be replaced.

-I input-format

The format of the input zone file. Possible formats are "text" (default) and "raw". This option is primarily intended to be used for dynamic signed zones so that the dumped zone file in a non-text format containing updates can be signed directly. The use of this option does not make much sense for non-dynamic zones.

-j jitter

When signing a zone with a fixed signature lifetime, all RRSIG records issued at the time of signing expires simultaneously. If the zone is incrementally signed, i.e. a previously signed zone is passed as input to the signer, all expired signatures has to be regenerated at about the same time. The jitter option specifies a jitter window that will be used to randomize the signature expire time, thus spreading incremental signature regeneration over time.

Signature lifetime jitter also to some extent benefits validators and servers by spreading out cache expiration, i.e. if large numbers of RRSIGs don't expire at the same time from all caches there will be less congestion than if all validators need to refetch at mostly the same time.

-n ncpus

Specifies the number of threads to use. By default, one thread is started for each detected CPU.

-o origin

The zone origin. If not specified, the name of the zone file is assumed to be the origin.

-O output-format

The format of the output file containing the signed zone. Possible formats are "text" (default) and "raw".


Use pseudo-random data when signing the zone. This is faster, but less secure, than using real random data. This option may be useful when signing large zones or when the entropy source is limited.

-r randomdev

Specifies the source of randomness. If the operating system does not provide a /dev/random or equivalent device, the default source of randomness is keyboard input. randomdev specifies the name of a character device or file containing random data to be used instead of the default. The special value keyboard indicates that keyboard input should be used.


Print statistics at completion.

-v level

Sets the debugging level.


Ignore KSK flag on key when determining what to sign.


The file containing the zone to be signed.


The keys used to sign the zone. If no keys are specified, the default all zone keys that have private key files in the current directory.


The following command signs the zone with the DSA key generated in the dnssec-keygen man page. The zone's keys must be in the zone. If there are keyset files associated with child zones, they must be in the current directory., the following command would be issued:

dnssec-signzone -o

The command would print a string of the form:

In this example, dnssec-signzone creates the file This file should be referenced in a zone statement in a named.conf file.


dnssec-keygen(8), BIND 9 Administrator Reference Manual, RFC 2535.


Internet Systems Consortium