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1064N/A<title>named</title>
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308N/A<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
308N/A<a name="man.named"></a><div class="titlepage"></div>
639N/A<div class="refnamediv">
308N/A<h2>Name</h2>
308N/A<p><span class="application">named</span> &#8212; Internet domain name server</p>
308N/A</div>
308N/A<div class="refsynopsisdiv">
308N/A<h2>Synopsis</h2>
308N/A<div class="cmdsynopsis"><p><code class="command">named</code> [<code class="option">-4</code>] [<code class="option">-6</code>] [<code class="option">-c <em class="replaceable"><code>config-file</code></em></code>] [<code class="option">-d <em class="replaceable"><code>debug-level</code></em></code>] [<code class="option">-D <em class="replaceable"><code>string</code></em></code>] [<code class="option">-E <em class="replaceable"><code>engine-name</code></em></code>] [<code class="option">-f</code>] [<code class="option">-g</code>] [<code class="option">-m <em class="replaceable"><code>flag</code></em></code>] [<code class="option">-n <em class="replaceable"><code>#cpus</code></em></code>] [<code class="option">-p <em class="replaceable"><code>port</code></em></code>] [<code class="option">-s</code>] [<code class="option">-S <em class="replaceable"><code>#max-socks</code></em></code>] [<code class="option">-t <em class="replaceable"><code>directory</code></em></code>] [<code class="option">-U <em class="replaceable"><code>#listeners</code></em></code>] [<code class="option">-u <em class="replaceable"><code>user</code></em></code>] [<code class="option">-v</code>] [<code class="option">-V</code>] [<code class="option">-x <em class="replaceable"><code>cache-file</code></em></code>]</p></div>
308N/A</div>
308N/A<div class="refsect1" lang="en">
308N/A<a name="id2543506"></a><h2>DESCRIPTION</h2>
308N/A<p><span><strong class="command">named</strong></span>
308N/A is a Domain Name System (DNS) server,
308N/A part of the BIND 9 distribution from ISC. For more
308N/A information on the DNS, see RFCs 1033, 1034, and 1035.
439N/A </p>
439N/A<p>
363N/A When invoked without arguments, <span><strong class="command">named</strong></span>
363N/A will
363N/A read the default configuration file
363N/A <code class="filename">/etc/named.conf</code>, read any initial
639N/A data, and listen for queries.
639N/A </p>
639N/A</div>
639N/A<div class="refsect1" lang="en">
639N/A<a name="id2543530"></a><h2>OPTIONS</h2>
639N/A<div class="variablelist"><dl>
639N/A<dt><span class="term">-4</span></dt>
384N/A<dd><p>
384N/A Use IPv4 only even if the host machine is capable of IPv6.
384N/A <code class="option">-4</code> and <code class="option">-6</code> are mutually
639N/A exclusive.
639N/A </p></dd>
639N/A<dt><span class="term">-6</span></dt>
639N/A<dd><p>
639N/A Use IPv6 only even if the host machine is capable of IPv4.
639N/A <code class="option">-4</code> and <code class="option">-6</code> are mutually
639N/A exclusive.
639N/A </p></dd>
639N/A<dt><span class="term">-c <em class="replaceable"><code>config-file</code></em></span></dt>
639N/A<dd><p>
639N/A Use <em class="replaceable"><code>config-file</code></em> as the
639N/A configuration file instead of the default,
1062N/A <code class="filename">/etc/named.conf</code>. To
639N/A ensure that reloading the configuration file continues
639N/A to work after the server has changed its working
639N/A directory due to to a possible
639N/A <code class="option">directory</code> option in the configuration
1062N/A file, <em class="replaceable"><code>config-file</code></em> should be
1062N/A an absolute pathname.
1062N/A </p></dd>
1062N/A<dt><span class="term">-d <em class="replaceable"><code>debug-level</code></em></span></dt>
1062N/A<dd><p>
1062N/A Set the daemon's debug level to <em class="replaceable"><code>debug-level</code></em>.
1062N/A Debugging traces from <span><strong class="command">named</strong></span> become
1062N/A more verbose as the debug level increases.
1062N/A </p></dd>
1062N/A<dt><span class="term">-D <em class="replaceable"><code>string</code></em></span></dt>
1062N/A<dd><p>
1062N/A Specifies a string that is used to identify a instance of
1062N/A <span><strong class="command">named</strong></span> in a process listing. The contents
1062N/A of <em class="replaceable"><code>string</code></em> are
1062N/A not examined.
1062N/A </p></dd>
1062N/A<dt><span class="term">-E <em class="replaceable"><code>engine-name</code></em></span></dt>
1062N/A<dd><p>
1062N/A Use a crypto hardware (OpenSSL engine) for the crypto operations
1062N/A it supports, for instance re-signing with private keys from
1062N/A a secure key store. When compiled with PKCS#11 support
1062N/A <em class="replaceable"><code>engine-name</code></em>
639N/A defaults to pkcs11, the empty name resets it to no engine.
639N/A </p></dd>
639N/A<dt><span class="term">-f</span></dt>
639N/A<dd><p>
639N/A Run the server in the foreground (i.e. do not daemonize).
639N/A </p></dd>
639N/A<dt><span class="term">-g</span></dt>
639N/A<dd><p>
639N/A Run the server in the foreground and force all logging
639N/A to <code class="filename">stderr</code>.
639N/A </p></dd>
639N/A<dt><span class="term">-m <em class="replaceable"><code>flag</code></em></span></dt>
639N/A<dd><p>
639N/A Turn on memory usage debugging flags. Possible flags are
308N/A <em class="replaceable"><code>usage</code></em>,
639N/A <em class="replaceable"><code>trace</code></em>,
639N/A <em class="replaceable"><code>record</code></em>,
639N/A <em class="replaceable"><code>size</code></em>, and
639N/A <em class="replaceable"><code>mctx</code></em>.
639N/A These correspond to the ISC_MEM_DEBUGXXXX flags described in
639N/A <code class="filename">&lt;isc/mem.h&gt;</code>.
639N/A </p></dd>
639N/A<dt><span class="term">-n <em class="replaceable"><code>#cpus</code></em></span></dt>
639N/A<dd><p>
639N/A Create <em class="replaceable"><code>#cpus</code></em> worker threads
639N/A to take advantage of multiple CPUs. If not specified,
639N/A <span><strong class="command">named</strong></span> will try to determine the
639N/A number of CPUs present and create one thread per CPU.
639N/A If it is unable to determine the number of CPUs, a
639N/A single worker thread will be created.
639N/A </p></dd>
639N/A<dt><span class="term">-p <em class="replaceable"><code>port</code></em></span></dt>
639N/A<dd><p>
639N/A Listen for queries on port <em class="replaceable"><code>port</code></em>. If not
639N/A specified, the default is port 53.
639N/A </p></dd>
639N/A<dt><span class="term">-s</span></dt>
639N/A<dd>
646N/A<p>
646N/A Write memory usage statistics to <code class="filename">stdout</code> on exit.
646N/A </p>
639N/A<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
646N/A<h3 class="title">Note</h3>
646N/A<p>
639N/A This option is mainly of interest to BIND 9 developers
646N/A and may be removed or changed in a future release.
646N/A </p>
639N/A</div>
639N/A</dd>
639N/A<dt><span class="term">-S <em class="replaceable"><code>#max-socks</code></em></span></dt>
639N/A<dd>
657N/A<p>
384N/A Allow <span><strong class="command">named</strong></span> to use up to
439N/A <em class="replaceable"><code>#max-socks</code></em> sockets.
384N/A </p>
384N/A<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
384N/A<h3 class="title">Warning</h3>
384N/A<p>
384N/A This option should be unnecessary for the vast majority
657N/A of users.
657N/A The use of this option could even be harmful because the
657N/A specified value may exceed the limitation of the
384N/A underlying system API.
363N/A It is therefore set only when the default configuration
363N/A causes exhaustion of file descriptors and the
464N/A operational environment is known to support the
439N/A specified number of sockets.
464N/A Note also that the actual maximum number is normally a little
464N/A fewer than the specified value because
464N/A <span><strong class="command">named</strong></span> reserves some file descriptors
439N/A for its internal use.
639N/A </p>
465N/A</div>
363N/A</dd>
464N/A<dt><span class="term">-t <em class="replaceable"><code>directory</code></em></span></dt>
363N/A<dd>
363N/A<p>Chroot
363N/A to <em class="replaceable"><code>directory</code></em> after
308N/A processing the command line arguments, but before
639N/A reading the configuration file.
308N/A </p>
363N/A<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
363N/A<h3 class="title">Warning</h3>
363N/A<p>
363N/A This option should be used in conjunction with the
363N/A <code class="option">-u</code> option, as chrooting a process
639N/A running as root doesn't enhance security on most
363N/A systems; the way <code class="function">chroot(2)</code> is
363N/A defined allows a process with root privileges to
363N/A escape a chroot jail.
363N/A </p>
363N/A</div>
657N/A</dd>
363N/A<dt><span class="term">-U <em class="replaceable"><code>#listeners</code></em></span></dt>
363N/A<dd><p>
363N/A Use <em class="replaceable"><code>#listeners</code></em>
363N/A worker threads to listen for incoming UDP packets on each
363N/A address. If not specified, <span><strong class="command">named</strong></span> will
363N/A use the number of detected CPUs. If <code class="option">-n</code>
363N/A has been set to a higher value than the number of CPUs,
363N/A then <code class="option">-U</code> may be increased as high as that
363N/A value, but no higher.
363N/A </p></dd>
363N/A<dt><span class="term">-u <em class="replaceable"><code>user</code></em></span></dt>
363N/A<dd>
363N/A<p>Setuid
363N/A to <em class="replaceable"><code>user</code></em> after completing
363N/A privileged operations, such as creating sockets that
308N/A listen on privileged ports.
363N/A </p>
363N/A<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
363N/A<h3 class="title">Note</h3>
1064N/A<p>
363N/A On Linux, <span><strong class="command">named</strong></span> uses the kernel's
363N/A capability mechanism to drop all root privileges
308N/A except the ability to <code class="function">bind(2)</code> to
a
privileged port and set process resource limits.
Unfortunately, this means that the <code class="option">-u</code>
option only works when <span><strong class="command">named</strong></span> 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 <code class="function">setuid(2)</code>.
</p>
</div>
</dd>
<dt><span class="term">-v</span></dt>
<dd><p>
Report the version number and exit.
</p></dd>
<dt><span class="term">-V</span></dt>
<dd><p>
Report the version number and build options, and exit.
</p></dd>
<dt><span class="term">-x <em class="replaceable"><code>cache-file</code></em></span></dt>
<dd>
<p>
Load data from <em class="replaceable"><code>cache-file</code></em> into the
cache of the default view.
</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3>
<p>
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.
</p>
</div>
</dd>
</dl></div>
</div>
<div class="refsect1" lang="en">
<a name="id2544117"></a><h2>SIGNALS</h2>
<p>
In routine operation, signals should not be used to control
the nameserver; <span><strong class="command">rndc</strong></span> should be used
instead.
</p>
<div class="variablelist"><dl>
<dt><span class="term">SIGHUP</span></dt>
<dd><p>
Force a reload of the server.
</p></dd>
<dt><span class="term">SIGINT, SIGTERM</span></dt>
<dd><p>
Shut down the server.
</p></dd>
</dl></div>
<p>
The result of sending any other signals to the server is undefined.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2544233"></a><h2>CONFIGURATION</h2>
<p>
The <span><strong class="command">named</strong></span> configuration file is too complex
to describe in detail here. A complete description is provided
in the
<em class="citetitle">BIND 9 Administrator Reference Manual</em>.
</p>
<p>
<span><strong class="command">named</strong></span> inherits the <code class="function">umask</code>
(file creation mode mask) from the parent process. If files
created by <span><strong class="command">named</strong></span>, such as journal files,
need to have custom permissions, the <code class="function">umask</code>
should be set explicitly in the script used to start the
<span><strong class="command">named</strong></span> process.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2544269"></a><h2>FILES</h2>
<div class="variablelist"><dl>
<dt><span class="term"><code class="filename">/etc/named.conf</code></span></dt>
<dd><p>
The default configuration file.
</p></dd>
<dt><span class="term"><code class="filename">/var/run/named/named.pid</code></span></dt>
<dd><p>
The default process-id file.
</p></dd>
</dl></div>
</div>
<div class="refsect1" lang="en">
<a name="id2544309"></a><h2>SEE ALSO</h2>
<p><em class="citetitle">RFC 1033</em>,
<em class="citetitle">RFC 1034</em>,
<em class="citetitle">RFC 1035</em>,
<span class="citerefentry"><span class="refentrytitle">named-checkconf</span>(8)</span>,
<span class="citerefentry"><span class="refentrytitle">named-checkzone</span>(8)</span>,
<span class="citerefentry"><span class="refentrytitle">rndc</span>(8)</span>,
<span class="citerefentry"><span class="refentrytitle">lwresd</span>(8)</span>,
<span class="citerefentry"><span class="refentrytitle">named.conf</span>(5)</span>,
<em class="citetitle">BIND 9 Administrator Reference Manual</em>.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2544379"></a><h2>AUTHOR</h2>
<p><span class="corpauthor">Internet Systems Consortium</span>
</p>
</div>
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