Commit c1ce2d23 authored by Shawn Routhier's avatar Shawn Routhier
Browse files

[rt29771]

[rt29770]
[rt29846]
Tidy up man pages, mostly convert a period followed by 1
or 3 spaces to a period followed by 2 spaces.  This also
covers tickets 29770 and 29846

Squashed commit of the following:

commit d40674fdfc8a81a44f8033bf048587a3eab0471f
Author: Shawn Routhier <sar@isc.org>
Date:   Fri Aug 3 17:55:05 2012 -0700
parent 5e1ef011
.\" $Id: dhclient.8,v 1.30.8.4.6.1 2011/04/15 22:26:20 sar Exp $
.\"
.\" Copyright (c) 2004,2007-2011 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2004,2007-2012 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 1996-2003 by Internet Software Consortium
.\"
.\" Permission to use, copy, modify, and distribute this software for any
......@@ -134,8 +134,8 @@ fail, by statically assigning an address.
.PP
The DHCP protocol allows a host to contact a central server which
maintains a list of IP addresses which may be assigned on one or more
subnets. A DHCP client may request an address from this pool, and
then use it on a temporary basis for communication on network. The
subnets. A DHCP client may request an address from this pool, and
then use it on a temporary basis for communication on network. The
DHCP protocol also provides a mechanism whereby a client can learn
important details about the network to which it is attached, such as
the location of a default router, the location of a name server, and
......@@ -149,20 +149,19 @@ or
options.
.PP
On startup, \fBdhclient\fR reads the dhclient.conf
.IR dhclient.conf
for configuration instructions. It then gets a list of all the
network interfaces that are configured in the current system. For
for configuration instructions. It then gets a list of all the
network interfaces that are configured in the current system. For
each interface, it attempts to configure the interface using the DHCP
protocol.
.PP
In order to keep track of leases across system reboots and server
restarts, \fBdhclient\fR keeps a list of leases it has been assigned in the
dhclient.leases file. On startup, after reading the dhclient.conf
dhclient.leases file. On startup, after reading the dhclient.conf
file, \fBdhclient\fR reads the dhclient.leases file to refresh its memory
about what leases it has been assigned.
.PP
When a new lease is acquired, it is appended to the end of the
dhclient.leases file. In order to prevent the file from becoming
dhclient.leases file. In order to prevent the file from becoming
arbitrarily large, from time to time \fBdhclient\fR creates a new
dhclient.leases file from its in-core lease database. The old version
of the dhclient.leases file is retained under the name
......@@ -171,19 +170,19 @@ until the next time \fBdhclient\fR rewrites the database.
.PP
Old leases are kept around in case the DHCP server is unavailable when
\fBdhclient\fR is first invoked (generally during the initial system boot
process). In that event, old leases from the dhclient.leases file
process). In that event, old leases from the dhclient.leases file
which have not yet expired are tested, and if they are determined to
be valid, they are used until either they expire or the DHCP server
becomes available.
.PP
A mobile host which may sometimes need to access a network on which no
DHCP server exists may be preloaded with a lease for a fixed
address on that network. When all attempts to contact a DHCP server
address on that network. When all attempts to contact a DHCP server
have failed, \fBdhclient\fR will try to validate the static lease, and if it
succeeds, will use that lease until it is restarted.
.PP
A mobile host may also travel to some networks on which DHCP is not
available but BOOTP is. In that case, it may be advantageous to
available but BOOTP is. In that case, it may be advantageous to
arrange with the network administrator for an entry on the BOOTP
database, so that the host can boot quickly on that network rather
than cycling through the list of old leases.
......@@ -196,7 +195,7 @@ network interfaces, eliminating non-broadcast interfaces if
possible, and attempt to configure each interface.
.PP
It is also possible to specify interfaces by name in the dhclient.conf
file. If interfaces are specified in this way, then the client will
file. If interfaces are specified in this way, then the client will
only configure interfaces that are either specified in the
configuration file or on the command line, and will ignore all other
interfaces.
......@@ -259,7 +258,7 @@ DHCP client will exit if it isn't able to identify any network interfaces
to configure. On laptop computers and other computers with
hot-swappable I/O buses, it is possible that a broadcast interface may
be added after system startup. This flag can be used to cause the client
not to exit when it doesn't find any such interfaces. The
not to exit when it doesn't find any such interfaces. The
.B omshell(1)
program can then be used to notify the client when a network interface
has been added or removed, so that the client can attempt to configure an IP
......@@ -397,28 +396,28 @@ client using TCP/IP, authenticate, and can then examine the client's
current status and make changes to it.
.PP
Rather than implementing the underlying OMAPI protocol directly, user
programs should use the dhcpctl API or OMAPI itself. Dhcpctl is a
programs should use the dhcpctl API or OMAPI itself. Dhcpctl is a
wrapper that handles some of the housekeeping chores that OMAPI does
not do automatically. Dhcpctl and OMAPI are documented in
not do automatically. Dhcpctl and OMAPI are documented in
\fBdhcpctl(3)\fR
and \fBomapi(3)\fR. Most things you'd want to do with the client can
and \fBomapi(3)\fR. Most things you'd want to do with the client can
be done directly using the \fBomshell(1)\fR command, rather than
having to write a special program.
.SH THE CONTROL OBJECT
The control object allows you to shut the client down, releasing all
leases that it holds and deleting any DNS records it may have added.
It also allows you to pause the client - this unconfigures any
interfaces the client is using. You can then restart it, which
causes it to reconfigure those interfaces. You would normally pause
interfaces the client is using. You can then restart it, which
causes it to reconfigure those interfaces. You would normally pause
the client prior to going into hibernation or sleep on a laptop
computer. You would then resume it after the power comes back.
computer. You would then resume it after the power comes back.
This allows PC cards to be shut down while the computer is hibernating
or sleeping, and then reinitialized to their previous state once the
computer comes out of hibernation or sleep.
.PP
The control object has one attribute - the state attribute. To shut
the client down, set its state attribute to 2. It will automatically
do a DHCPRELEASE. To pause it, set its state attribute to 3. To
The control object has one attribute - the state attribute. To shut
the client down, set its state attribute to 2. It will automatically
do a DHCPRELEASE. To pause it, set its state attribute to 3. To
resume it, set its state attribute to 4.
.PP
.SH ENVIRONMENT VARIABLES
......@@ -465,7 +464,7 @@ Stanford.
The current version owes much to Elliot's Linux enhancements, but
was substantially reorganized and partially rewritten by Ted Lemon
so as to use the same networking framework that the Internet Systems
Consortium DHCP server uses. Much system-specific configuration code
Consortium DHCP server uses. Much system-specific configuration code
was moved into a shell script so that as support for more operating
systems is added, it will not be necessary to port and maintain
system-specific configuration code to these operating systems - instead,
......
This diff is collapsed.
.\" $Id: dhcp-eval.5,v 1.27.364.3.6.2 2012/05/17 15:52:27 sar Exp $
.\"
.\" Copyright (c) 2009-2011 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2009-2012 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 1996-2003 by Internet Software Consortium
.\"
......@@ -34,35 +34,35 @@ dhcp-eval - ISC DHCP conditional evaluation
.SH DESCRIPTION
The Internet Systems Consortium DHCP client and server both provide
the ability to perform conditional behavior depending on the contents
of packets they receive. The syntax for specifying this conditional
of packets they receive. The syntax for specifying this conditional
behaviour is documented here.
.SH REFERENCE: CONDITIONAL BEHAVIOUR
Conditional behaviour is specified using the if statement and the else
or elsif statements. A conditional statement can appear anywhere
or elsif statements. A conditional statement can appear anywhere
that a regular statement (e.g., an option statement) can appear, and
can enclose one or more such statements. A typical conditional
can enclose one or more such statements. A typical conditional
statement in a server might be:
.PP
.nf
if option dhcp-user-class = "accounting" {
max-lease-time 17600;
option domain-name "accounting.example.org";
option domain-name-servers ns1.accounting.example.org,
option domain-name-servers ns1.accounting.example.org,
ns2.accounting.example.org;
} elsif option dhcp-user-class = "sales" {
max-lease-time 17600;
option domain-name "sales.example.org";
option domain-name-servers ns1.sales.example.org,
option domain-name-servers ns1.sales.example.org,
ns2.sales.example.org;
} elsif option dhcp-user-class = "engineering" {
max-lease-time 17600;
option domain-name "engineering.example.org";
option domain-name-servers ns1.engineering.example.org,
option domain-name-servers ns1.engineering.example.org,
ns2.engineering.example.org;
} else {
max-lease-time 600;
option domain-name "misc.example.org";
option domain-name-servers ns1.misc.example.org,
option domain-name-servers ns1.misc.example.org,
ns2.misc.example.org;
}
.fi
......@@ -71,36 +71,36 @@ On the client side, an example of conditional evaluation might be:
.PP
.nf
# example.org filters DNS at its firewall, so we have to use their DNS
# servers when we connect to their network. If we are not at
# servers when we connect to their network. If we are not at
# example.org, prefer our own DNS server.
if not option domain-name = "example.org" {
prepend domain-name-servers 127.0.0.1;
}
.fi
.fi
.PP
The
.B if
statement and the
.B elsif
continuation statement both take boolean expressions as their
arguments. That is, they take expressions that, when evaluated,
produce a boolean result. If the expression evaluates to true, then
the statements enclosed in braces following the
arguments. That is, they take expressions that, when evaluated,
produce a boolean result. If the expression evaluates to true, then
the statements enclosed in braces following the
.B if
statement are executed, and all subsequent
.B elsif
and
.B else
clauses are skipped. Otherwise, each subsequent
clauses are skipped. Otherwise, each subsequent
.B elsif
clause's expression is checked, until an elsif clause is encountered
whose test evaluates to true. If such a clause is found, the
whose test evaluates to true. If such a clause is found, the
statements in braces following it are executed, and then any
subsequent
.B elsif
and
.B else
clauses are skipped. If all the
clauses are skipped. If all the
.B if
and
.B elsif
......@@ -109,7 +109,7 @@ of their expressions evaluate true, then if there is an
.B else
clause, the statements enclosed in braces following the
.B else
are evaluated. Boolean expressions that evaluate to null are
are evaluated. Boolean expressions that evaluate to null are
treated as false in conditionals.
.SH BOOLEAN EXPRESSIONS
The following is the current list of boolean expressions that are
......@@ -119,7 +119,7 @@ supported by the DHCP distribution.
.RS 0.25i
.PP
The \fB=\fR operator compares the values of two data expressions,
returning true if they are the same, false if they are not. If
returning true if they are the same, false if they are not. If
either the left-hand side or the right-hand side are null, the
result is also null.
.RE
......@@ -132,7 +132,7 @@ The \fB~=\fR and \fB~~\fR operators (not available on all systems) perform
extended regex(7) matching of the values of two data expressions, returning
true if \fIdata-expression-1\fR matches against the regular expression
evaluated by \fIdata-expression-2\fR, or false if it does not match or
encounters some error. If either the left-hand side or the right-hand side
encounters some error. If either the left-hand side or the right-hand side
are null or empty strings, the result is also false. The \fB~~\fR operator
differs from the \fB~=\fR operator in that it is case-insensitive.
.RE
......@@ -162,7 +162,7 @@ the right-hand side are null, the result is null.
.RS 0.25i
The \fBnot\fR operator evaluates to true if \fIboolean-expression\fR
evaluates to false, and returns false if \fIboolean-expression\fR evaluates
to true. If \fIboolean-expression\fR evaluates to null, the result
to true. If \fIboolean-expression\fR evaluates to null, the result
is also null.
.RE
.PP
......@@ -188,7 +188,7 @@ address assignment.
.RE
.SH DATA EXPRESSIONS
Several of the boolean expressions above depend on the results of
evaluating data expressions. A list of these expressions is provided
evaluating data expressions. A list of these expressions is provided
here.
.PP
.B substring (\fIdata-expr\fB, \fIoffset\fB, \fIlength\fB)\fR
......@@ -211,7 +211,7 @@ is returned.
.PP
.RS 0.25i
The \fBsuffix\fR operator evaluates \fIdata-expr\fR and returns the
last \fIlength\fR bytes of the result of that evaluation. \fILength\fR
last \fIlength\fR bytes of the result of that evaluation. \fILength\fR
is a numeric expression. If \fIdata-expr\fR or \fIlength\fR evaluate
to null, then the result is also null. If \fIsuffix\fR evaluates to a
number greater than the length of the evaluated data, then the
......@@ -222,7 +222,7 @@ evaluated data is returned.
.PP
.RS 0.25i
The \fBlcase\fR function returns the result of evaluating
\fIdata-expr\fR converted to lower case. If \fIdata-expr\fR evaluates
\fIdata-expr\fR converted to lower case. If \fIdata-expr\fR evaluates
to null, then the result is also null.
.RE
.PP
......@@ -230,7 +230,7 @@ to null, then the result is also null.
.PP
.RS 0.25i
The \fBucase\fR function returns the result of evaluating
\fIdata-expr\fR converted to upper case. If \fIdata-expr\fR evaluates
\fIdata-expr\fR converted to upper case. If \fIdata-expr\fR evaluates
to null, then the result is also null.
.RE
.PP
......@@ -253,10 +253,10 @@ that the DHCP client or server has been configured to send.
.RS 0.25i
The \fBhardware\fR operator returns a data string whose first element
is the type of network interface indicated in packet being considered,
and whose subsequent elements are client's link-layer address. If
and whose subsequent elements are client's link-layer address. If
there is no packet, or if the RFC2131 \fIhlen\fR field is invalid,
then the result is null. Hardware types include ethernet (1),
token-ring (6), and fddi (8). Hardware types are specified by the
then the result is null. Hardware types include ethernet (1),
token-ring (6), and fddi (8). Hardware types are specified by the
IETF, and details on how the type numbers are defined can be found in
RFC2131 (in the ISC DHCP distribution, this is included in the doc/
subdirectory).
......@@ -267,7 +267,7 @@ subdirectory).
.RS 0.25i
The \fBpacket\fR operator returns the specified portion of the packet
being considered, or null in contexts where no packet is being
considered. \fIOffset\fR and \fIlength\fR are applied to the
considered. \fIOffset\fR and \fIlength\fR are applied to the
contents packet as in the \fBsubstring\fR operator.
.RE
.PP
......@@ -275,10 +275,10 @@ contents packet as in the \fBsubstring\fR operator.
.PP
.RS 0.25i
A string, enclosed in quotes, may be specified as a data expression,
and returns the text between the quotes, encoded in ASCII. The
and returns the text between the quotes, encoded in ASCII. The
backslash ('\\') character is treated specially, as in C programming: '\\t'
means TAB, '\\r' means carriage return, '\\n' means newline, and '\\b' means
bell. Any octal value can be specified with '\\nnn', where nnn is any
bell. Any octal value can be specified with '\\nnn', where nnn is any
positive octal number less than 0400. Any hexadecimal value can be
specified with '\\xnn', where nn is any positive hexadecimal number less
than or equal to 0xff.
......@@ -294,7 +294,7 @@ specified as a data expression.
.B concat (\fIdata-expr1\fB, ..., \fIdata-exprN\fB)\fR
.RS 0.25i
The expressions are evaluated, and the results of each evaluation are
concatenated in the sequence that the subexpressions are listed. If
concatenated in the sequence that the subexpressions are listed. If
any subexpression evaluates to null, the result of the concatenation
is null.
.RE
......@@ -303,8 +303,8 @@ is null.
.RS 0.25i
The two expressions are evaluated, and then the result of evaluating
the data expression is reversed in place, using hunks of the size
specified in the numeric expression. For example, if the numeric
expression evaluates to four, and the data expression evaluates to
specified in the numeric expression. For example, if the numeric
expression evaluates to four, and the data expression evaluates to
twelve bytes of data, then the reverse expression will evaluate to
twelve bytes of data, consisting of the last four bytes of the the
input data, followed by the middle four bytes, followed by the first
......@@ -328,10 +328,10 @@ information).
.RS 0.25i
Converts the result of evaluating data-expr2 into a text string
containing one number for each element of the result of evaluating
data-expr2. Each number is separated from the other by the result of
evaluating data-expr1. The result of evaluating numeric-expr1
data-expr2. Each number is separated from the other by the result of
evaluating data-expr1. The result of evaluating numeric-expr1
specifies the base (2 through 16) into which the numbers should be
converted. The result of evaluating numeric-expr2 specifies the
converted. The result of evaluating numeric-expr2 specifies the
width in bits of each number, which may be either 8, 16 or 32.
.PP
As an example of the preceding three types of expressions, to produce
......@@ -358,10 +358,10 @@ also null.
.B pick-first-value (\fIdata-expr1\fR [ ... \fIexpr\fRn ] \fB)\fR
.RS 0.25i
The pick-first-value function takes any number of data expressions as
its arguments. Each expression is evaluated, starting with the first
its arguments. Each expression is evaluated, starting with the first
in the list, until an expression is found that does not evaluate to a
null value. That expression is returned, and none of the subsequent
expressions are evaluated. If all expressions evaluate to a null
null value. That expression is returned, and none of the subsequent
expressions are evaluated. If all expressions evaluate to a null
value, the null value is returned.
.RE
.PP
......@@ -369,10 +369,10 @@ value, the null value is returned.
.RS 0.25i
The host-decl-name function returns the name of the host declaration
that matched the client whose request is currently being processed, if
any. If no host declaration matched, the result is the null value.
any. If no host declaration matched, the result is the null value.
.RE
.SH NUMERIC EXPRESSIONS
Numeric expressions are expressions that evaluate to an integer. In
Numeric expressions are expressions that evaluate to an integer. In
general, the maximum size of such an integer should not be assumed to
be representable in fewer than 32 bits, but the precision of such
integers may be more than 32 bits.
......@@ -382,8 +382,8 @@ integers may be more than 32 bits.
.RS 0.25i
The \fBextract-int\fR operator extracts an integer value in network
byte order from the result of evaluating the specified data
expression. Width is the width in bits of the integer to extract.
Currently, the only supported widths are 8, 16 and 32. If the
expression. Width is the width in bits of the integer to extract.
Currently, the only supported widths are 8, 16 and 32. If the
evaluation of the data expression doesn't provide sufficient bits to
extract an integer of the specified size, the null value is returned.
.RE
......@@ -405,45 +405,45 @@ specified as a numeric expression.
.B client-state
.PP
.RS 0.25i
The current state of the client instance being processed. This is
only useful in DHCP client configuration files. Possible values are:
The current state of the client instance being processed. This is
only useful in DHCP client configuration files. Possible values are:
.TP 2
.I \(bu
Booting - DHCP client is in the INIT state, and does not yet have an
IP address. The next message transmitted will be a DHCPDISCOVER,
IP address. The next message transmitted will be a DHCPDISCOVER,
which will be broadcast.
.TP
.I \(bu
Reboot - DHCP client is in the INIT-REBOOT state. It has an IP
address, but is not yet using it. The next message to be transmitted
will be a DHCPREQUEST, which will be broadcast. If no response is
Reboot - DHCP client is in the INIT-REBOOT state. It has an IP
address, but is not yet using it. The next message to be transmitted
will be a DHCPREQUEST, which will be broadcast. If no response is
heard, the client will bind to its address and move to the BOUND state.
.TP
.I \(bu
Select - DHCP client is in the SELECTING state - it has received at
least one DHCPOFFER message, but is waiting to see if it may receive
other DHCPOFFER messages from other servers. No messages are sent in
other DHCPOFFER messages from other servers. No messages are sent in
the SELECTING state.
.TP
.I \(bu
Request - DHCP client is in the REQUESTING state - it has received at
least one DHCPOFFER message, and has chosen which one it will
request. The next message to be sent will be a DHCPREQUEST message,
request. The next message to be sent will be a DHCPREQUEST message,
which will be broadcast.
.TP
.I \(bu
Bound - DHCP client is in the BOUND state - it has an IP address. No
Bound - DHCP client is in the BOUND state - it has an IP address. No
messages are transmitted in this state.
.TP
.I \(bu
Renew - DHCP client is in the RENEWING state - it has an IP address,
and is trying to contact the server to renew it. The next message to
and is trying to contact the server to renew it. The next message to
be sent will be a DHCPREQUEST message, which will be unicast directly
to the server.
.TP
.I \(bu
Rebind - DHCP client is in the REBINDING state - it has an IP address,
and is trying to contact any server to renew it. The next message to
and is trying to contact any server to renew it. The next message to
be sent will be a DHCPREQUEST, which will be broadcast.
.RE
.SH REFERENCE: ACTION EXPRESSIONS
......@@ -482,7 +482,7 @@ octal escapes ("\\nnn"), make sure your external command handles them as
such.
.PP
It is possible to use the execute statement in any context, not only
on events. If you put it in a regular scope in the configuration file
on events. If you put it in a regular scope in the configuration file
you will execute that command every time a scope is evaluated.
.RE
.SH REFERENCE: DYNAMIC DNS UPDATES
......
This diff is collapsed.
.\" $Id: omshell.1,v 1.4.690.2 2009/07/24 22:04:52 sar Exp $
.\"
.\" Copyright (c) 2012 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2004,2009 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2001-2003 by Internet Software Consortium
.\"
......@@ -25,7 +26,7 @@
.\" by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
.\" To learn more about Internet Systems Consortium, see
.\" ``https://www.isc.org/''. To learn more about Vixie Enterprises,
.\" see ``http://www.vix.com''. To learn more about Nominum, Inc., see
.\" see ``http://www.vix.com''. To learn more about Nominum, Inc., see
.\" ``http://www.nominum.com''.
.TH omshell 1
.SH NAME
......@@ -37,11 +38,11 @@ The OMAPI Command Shell, omshell, provides an interactive way to connect to,
query, and possibly change, the ISC DHCP Server's state via OMAPI, the Object
Management API. By using OMAPI and omshell, you do not have to stop, make
changes, and then restart the DHCP server, but can make the changes
while the server is running. Omshell provides a way of accessing
while the server is running. Omshell provides a way of accessing
OMAPI.
.PP
OMAPI is simply a communications mechanism that allows you to
manipulate objects. In order to actually \fIuse\fR omshell, you
manipulate objects. In order to actually \fIuse\fR omshell, you
.I must
understand what objects are available and how to use them.
Documentation for OMAPI objects can be found in the documentation for
......@@ -276,7 +277,7 @@ dhcpd.conf, but was created dynamically via OMAPI.
.SH RESETTING ATTRIBUTES
.PP
If you want to remove an attribute from an object, you can do this with the
\fBunset\fR command. Once you have unset an attribute, you must use the
\fBunset\fR command. Once you have unset an attribute, you must use the
\fBupdate\fR command to update the remote object. So, if the host "some-host"
from the previous example will not have a static IP address anymore, the
commands in omshell would look like this:
......
.\" dhcrelay.8
.\"
.\" Copyright (c) 2009-2011 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2009-2012 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 1997-2003 by Internet Software Consortium
.\"
......@@ -176,7 +176,7 @@ will write a pid file.
.TP
-a
Append an agent option field to each request before forwarding it to
the server. Agent option fields in responses sent from servers to
the server. Agent option fields in responses sent from servers to
clients will be stripped before forwarding such responses back to the
client. The agent option field will contain two agent options: the Circuit
ID suboption and the Remote ID suboption. Currently, the Circuit ID will
......
.\" dhcpd.8
.\"
.\" Copyright (c) 2009-2011 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2009-2012 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 2004-2007 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 1996-2003 by Internet Software Consortium
.\"
......@@ -105,7 +105,7 @@ functionality, with certain restrictions.
.PP
The DHCP protocol allows a host which is unknown to the network
administrator to be automatically assigned a new IP address out of a
pool of IP addresses for its network. In order for this to work, the
pool of IP addresses for its network. In order for this to work, the
network administrator allocates address pools in each subnet and
enters them into the dhcpd.conf(5) file.
.PP
......@@ -130,30 +130,30 @@ address.
.PP
In order to keep track of leases across system reboots and server
restarts, dhcpd keeps a list of leases it has assigned in the
dhcpd.leases(5) file. Before dhcpd grants a lease to a host, it
dhcpd.leases(5) file. Before dhcpd grants a lease to a host, it
records the lease in this file and makes sure that the contents of the
file are flushed to disk. This ensures that even in the event of a
file are flushed to disk. This ensures that even in the event of a
system crash, dhcpd will not forget about a lease that it has
assigned. On startup, after reading the dhcpd.conf file, dhcpd
assigned. On startup, after reading the dhcpd.conf file, dhcpd
reads the dhcpd.leases file to refresh its memory about what leases
have been assigned.
.PP
New leases are appended to the end of the dhcpd.leases
file. In order to prevent the file from becoming arbitrarily large,
file. In order to prevent the file from becoming arbitrarily large,
from time to time dhcpd creates a new dhcpd.leases file from its
in-core lease database. Once this file has been written to disk, the
old file is renamed
.IR dhcpd.leases~ ,
and the new file is renamed dhcpd.leases. If the system crashes in
and the new file is renamed dhcpd.leases. If the system crashes in
the middle of this process, whichever dhcpd.leases file remains will
contain all the lease information, so there is no need for a special
crash recovery process.
.PP
BOOTP support is also provided by this server. Unlike DHCP, the BOOTP
protocol does not provide a protocol for recovering
dynamically-assigned addresses once they are no longer needed. It is
dynamically-assigned addresses once they are no longer needed. It is
still possible to dynamically assign addresses to BOOTP clients, but
some administrative process for reclaiming addresses is required. By
some administrative process for reclaiming addresses is required. By
default, leases are granted to BOOTP clients in perpetuity, although
the network administrator may set an earlier cutoff date or a shorter
lease length for BOOTP leases if that makes sense.
......@@ -163,18 +163,18 @@ simply provide a declaration in the dhcpd.conf file for each
BOOTP client, permanently assigning an address to each client.
.PP
Whenever changes are made to the dhcpd.conf file, dhcpd must be
restarted. To restart dhcpd, send a SIGTERM (signal 15) to the
restarted. To restart dhcpd, send a SIGTERM (signal 15) to the
process ID contained in
.IR RUNDIR/dhcpd.pid ,
and then re-invoke dhcpd. Because the DHCP server database is not as
lightweight as a BOOTP database, dhcpd does not automatically restart
itself when it sees a change to the dhcpd.conf file.
.PP
Note: We get a lot of complaints about this. We realize that it would
Note: We get a lot of complaints about this. We realize that it would
be nice if one could send a SIGHUP to the server and have it reload
the database. This is not technically impossible, but it would
the database. This is not technically impossible, but it would
require a great deal of work, our resources are extremely limited, and
they can be better spent elsewhere. So please don't complain about
they can be better spent elsewhere. So please don't complain about
this on the mailing list unless you're prepared to fund a project to
implement this feature, or prepared to do it yourself.
.SH COMMAND LINE
......@@ -223,7 +223,7 @@ out of inittab on System V systems.
Send log messages to the standard error descriptor.
This can be useful for debugging, and also at sites where a
complete log of all dhcp activity must be kept but syslogd is not
reliable or otherwise cannot be used. Normally,
reliable or otherwise cannot be used. Normally,
.B dhcpd
will log all
output using the \fBsyslog(3)\fR function with the log facility set to
......@@ -240,13 +240,13 @@ from a system startup script (e.g., /etc/rc).
.BI \-t
Test the configuration file. The server tests the configuration file
for correct syntax, but will not attempt to perform any network
operations. This can be used to test a new configuration file
operations. This can be used to test a new configuration file
automatically before installing it.
.TP
.BI \-T
Test the lease file. The server tests the lease file
for correct syntax, but will not attempt to perform any network
operations. This can be used to test a new leaes file
operations. This can be used to test a new leaes file
automatically before installing it.
.TP
.BI \-tf \ tracefile
......@@ -293,17 +293,17 @@ will write a pid file. If the program is invoked with this
option it will not check for an existing server process.
.PP
.SH CONFIGURATION
The syntax of the dhcpd.conf(5) file is discussed separately. This
The syntax of the dhcpd.conf(5) file is discussed separately. This
section should be used as an overview of the configuration process,
and the dhcpd.conf(5) documentation should be consulted for detailed
reference information.
.PP
.SH Subnets
dhcpd needs to know the subnet numbers and netmasks of all subnets for
which it will be providing service. In addition, in order to
which it will be providing service. In addition, in order to
dynamically allocate addresses, it must be assigned one or more ranges
of addresses on each subnet which it can in turn assign to client
hosts as they boot. Thus, a very simple configuration providing DHCP
hosts as they boot. Thus, a very simple configuration providing DHCP
support might look like this:
.nf
.sp 1
......@@ -327,21 +327,21 @@ subnet statement must appear.
.PP
.SH Lease Lengths
DHCP leases can be assigned almost any length from zero seconds to
infinity. What lease length makes sense for any given subnet, or for
infinity. What lease length makes sense for any given subnet, or for
any given installation, will vary depending on the kinds of hosts
being served.
.PP
For example, in an office environment where systems are added from
time to time and removed from time to time, but move relatively
infrequently, it might make sense to allow lease times of a month or
more. In a final test environment on a manufacturing floor, it may
more. In a final test environment on a manufacturing floor, it may
make more sense to assign a maximum lease length of 30 minutes -
enough time to go through a simple test procedure on a network
appliance before packaging it up for delivery.
.PP
It is possible to specify two lease lengths: the default length that
will be assigned if a client doesn't ask for any particular lease
length, and a maximum lease length. These are specified as clauses
length, and a maximum lease length. These are specified as clauses
to the subnet command:
.nf
.sp 1
......@@ -354,7 +354,7 @@ to the subnet command:
.PP
This particular subnet declaration specifies a default lease time of
600 seconds (ten minutes), and a maximum lease time of 7200 seconds
(two hours). Other common values would be 86400 (one day), 604800