.\" Copyright (C) 2004-2009, 2011, 2013-2015 Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (C) 2000, 2001, 2003 Internet Software Consortium.
.\" 
.\" Permission to use, copy, modify, and/or distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\" 
.\" THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
.\" REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
.\" AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
.\" LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
.\" OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
.\" PERFORMANCE OF THIS SOFTWARE.
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.\" $Id$
.\"
.hy 0
.ad l
.\"     Title: named
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.71.1 <http://docbook.sf.net/>
.\"      Date: February 19, 2014
.\"    Manual: BIND9
.\"    Source: BIND9
.\"
.TH "NAMED" "8" "February 19, 2014" "BIND9" "BIND9"
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.SH "NAME"
named \- Internet domain name server
.SH "SYNOPSIS"
.HP 6
\fBnamed\fR [\fB\-4\fR] [\fB\-6\fR] [\fB\-c\ \fR\fB\fIconfig\-file\fR\fR] [\fB\-d\ \fR\fB\fIdebug\-level\fR\fR] [\fB\-D\ \fR\fB\fIstring\fR\fR] [\fB\-E\ \fR\fB\fIengine\-name\fR\fR] [\fB\-f\fR] [\fB\-g\fR] [\fB\-M\ \fR\fB\fIoption\fR\fR] [\fB\-m\ \fR\fB\fIflag\fR\fR] [\fB\-n\ \fR\fB\fI#cpus\fR\fR] [\fB\-p\ \fR\fB\fIport\fR\fR] [\fB\-s\fR] [\fB\-S\ \fR\fB\fI#max\-socks\fR\fR] [\fB\-t\ \fR\fB\fIdirectory\fR\fR] [\fB\-U\ \fR\fB\fI#listeners\fR\fR] [\fB\-u\ \fR\fB\fIuser\fR\fR] [\fB\-v\fR] [\fB\-V\fR] [\fB\-x\ \fR\fB\fIcache\-file\fR\fR]
.SH "DESCRIPTION"
.PP
\fBnamed\fR
is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFCs 1033, 1034, and 1035.
.PP
When invoked without arguments,
\fBnamed\fR
will read the default configuration file
\fI/etc/named.conf\fR, read any initial data, and listen for queries.
.SH "OPTIONS"
.PP
\-4
.RS 4
Use IPv4 only even if the host machine is capable of IPv6.
\fB\-4\fR
and
\fB\-6\fR
are mutually exclusive.
.RE
.PP
\-6
.RS 4
Use IPv6 only even if the host machine is capable of IPv4.
\fB\-4\fR
and
\fB\-6\fR
are mutually exclusive.
.RE
.PP
\-c \fIconfig\-file\fR
.RS 4
Use
\fIconfig\-file\fR
as the configuration file instead of the default,
\fI/etc/named.conf\fR. To ensure that reloading the configuration file continues to work after the server has changed its working directory due to to a possible
\fBdirectory\fR
option in the configuration file,
\fIconfig\-file\fR
should be an absolute pathname.
.RE
.PP
\-d \fIdebug\-level\fR
.RS 4
Set the daemon's debug level to
\fIdebug\-level\fR. Debugging traces from
\fBnamed\fR
become more verbose as the debug level increases.
.RE
.PP
\-D \fIstring\fR
.RS 4
Specifies a string that is used to identify a instance of
\fBnamed\fR
in a process listing. The contents of
\fIstring\fR
are not examined.
.RE
.PP
\-E \fIengine\-name\fR
.RS 4
When applicable, specifies the hardware to use for cryptographic operations, such as a secure key store used for signing.
.sp
When BIND is built with OpenSSL PKCS#11 support, this defaults to the string "pkcs11", which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (\-\-enable\-native\-pkcs11), it defaults to the path of the PKCS#11 provider library specified via "\-\-with\-pkcs11".
.RE
.PP
\-f
.RS 4
Run the server in the foreground (i.e. do not daemonize).
.RE
.PP
\-g
.RS 4
Run the server in the foreground and force all logging to
\fIstderr\fR.
.RE
.PP
\-M \fIoption\fR
.RS 4
Sets the default memory context options. Currently the only supported option is
\fIexternal\fR, which causes the internal memory manager to be bypassed in favor of system\-provided memory allocation functions.
.RE
.PP
\-m \fIflag\fR
.RS 4
Turn on memory usage debugging flags. Possible flags are
\fIusage\fR,
\fItrace\fR,
\fIrecord\fR,
\fIsize\fR, and
\fImctx\fR. These correspond to the ISC_MEM_DEBUGXXXX flags described in
\fI<isc/mem.h>\fR.
.RE
.PP
\-n \fI#cpus\fR
.RS 4
Create
\fI#cpus\fR
worker threads to take advantage of multiple CPUs. If not specified,
\fBnamed\fR
will try to determine the number of CPUs present and create one thread per CPU. If it is unable to determine the number of CPUs, a single worker thread will be created.
.RE
.PP
\-p \fIport\fR
.RS 4
Listen for queries on port
\fIport\fR. If not specified, the default is port 53.
.RE
.PP
\-s
.RS 4
Write memory usage statistics to
\fIstdout\fR
on exit.
.RS
.B "Note:"
This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.
.RE
.RE
.PP
\-S \fI#max\-socks\fR
.RS 4
Allow
\fBnamed\fR
to use up to
\fI#max\-socks\fR
sockets. The default value is 4096 on systems built with default configuration options, and 21000 on systems built with "configure \-\-with\-tuning=large".
.RS
.B "Warning:"
This option should be unnecessary for the vast majority of users. The use of this option could even be harmful because the specified value may exceed the limitation of the underlying system API. It is therefore set only when the default configuration causes exhaustion of file descriptors and the operational environment is known to support the specified number of sockets. Note also that the actual maximum number is normally a little fewer than the specified value because
\fBnamed\fR
reserves some file descriptors for its internal use.
.RE
.RE
.PP
\-t \fIdirectory\fR
.RS 4
Chroot to
\fIdirectory\fR
after processing the command line arguments, but before reading the configuration file.
.RS
.B "Warning:"
This option should be used in conjunction with the
\fB\-u\fR
option, as chrooting a process running as root doesn't enhance security on most systems; the way
\fBchroot(2)\fR
is defined allows a process with root privileges to escape a chroot jail.
.RE
.RE
.PP
\-U \fI#listeners\fR
.RS 4
Use
\fI#listeners\fR
worker threads to listen for incoming UDP packets on each address. If not specified,
\fBnamed\fR
will calculate a default value based on the number of detected CPUs: 1 for 1 CPU, 2 for 2\-4 CPUs, and the number of detected CPUs divided by 2 for values higher than 4. If
\fB\-n\fR
has been set to a higher value than the number of detected CPUs, then
\fB\-U\fR
may be increased as high as that value, but no higher.
.RE
.PP
\-u \fIuser\fR
.RS 4
Setuid to
\fIuser\fR
after completing privileged operations, such as creating sockets that listen on privileged ports.
.RS
.B "Note:"
On Linux,
\fBnamed\fR
uses the kernel's capability mechanism to drop all root privileges except the ability to
\fBbind(2)\fR
to a privileged port and set process resource limits. Unfortunately, this means that the
\fB\-u\fR
option only works when
\fBnamed\fR
is run on kernel 2.2.18 or later, or kernel 2.3.99\-pre3 or later, since previous kernels did not allow privileges to be retained after
\fBsetuid(2)\fR.
.RE
.RE
.PP
\-v
.RS 4
Report the version number and exit.
.RE
.PP
\-V
.RS 4
Report the version number and build options, and exit.
.RE
.PP
\-x \fIcache\-file\fR
.RS 4
Load data from
\fIcache\-file\fR
into the cache of the default view.
.RS
.B "Warning:"
This option must not be used. It is only of interest to BIND 9 developers and may be removed or changed in a future release.
.RE
.RE
.SH "SIGNALS"
.PP
In routine operation, signals should not be used to control the nameserver;
\fBrndc\fR
should be used instead.
.PP
SIGHUP
.RS 4
Force a reload of the server.
.RE
.PP
SIGINT, SIGTERM
.RS 4
Shut down the server.
.RE
.PP
The result of sending any other signals to the server is undefined.
.SH "CONFIGURATION"
.PP
The
\fBnamed\fR
configuration file is too complex to describe in detail here. A complete description is provided in the
BIND 9 Administrator Reference Manual.
.PP
\fBnamed\fR
inherits the
\fBumask\fR
(file creation mode mask) from the parent process. If files created by
\fBnamed\fR, such as journal files, need to have custom permissions, the
\fBumask\fR
should be set explicitly in the script used to start the
\fBnamed\fR
process.
.SH "FILES"
.PP
\fI/etc/named.conf\fR
.RS 4
The default configuration file.
.RE
.PP
\fI/var/run/named/named.pid\fR
.RS 4
The default process\-id file.
.RE
.SH "SEE ALSO"
.PP
RFC 1033,
RFC 1034,
RFC 1035,
\fBnamed\-checkconf\fR(8),
\fBnamed\-checkzone\fR(8),
\fBrndc\fR(8),
\fBlwresd\fR(8),
\fBnamed.conf\fR(5),
BIND 9 Administrator Reference Manual.
.SH "AUTHOR"
.PP
Internet Systems Consortium
.SH "COPYRIGHT"
Copyright \(co 2004\-2009, 2011, 2013\-2015 Internet Systems Consortium, Inc. ("ISC")
.br
Copyright \(co 2000, 2001, 2003 Internet Software Consortium.
.br