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582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews - purpose with or without fee is hereby granted, provided that the above
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582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<title>Chapter�3.�Name Server Configuration</title>
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582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<tr><th colspan="3" align="center">Chapter�3.�Name Server Configuration</th></tr>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<tr>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td width="20%" align="left">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<a accesskey="p" href="Bv9ARM.ch02.html">Prev</a>�</td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<th width="60%" align="center">�</th>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td width="20%" align="right">�<a accesskey="n" href="Bv9ARM.ch04.html">Next</a>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</tr>
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582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<hr>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="chapter" lang="en">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="titlepage"><div><div><h2 class="title">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<a name="Bv9ARM.ch03"></a>Chapter�3.�Name Server Configuration</h2></div></div></div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="toc">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<p><b>Table of Contents</b></p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<dl>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<dt><span class="sect1"><a href="Bv9ARM.ch03.html#sample_configuration">Sample Configurations</a></span></dt>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<dd><dl>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2548733">A Caching-only Name Server</a></span></dt>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2548749">An Authoritative-only Name Server</a></span></dt>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</dl></dd>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<dt><span class="sect1"><a href="Bv9ARM.ch03.html#id2548772">Load Balancing</a></span></dt>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater<dt><span class="sect1"><a href="Bv9ARM.ch03.html#id2549264">Name Server Operations</a></span></dt>
922312472e2e05ebc64993d465999c5351b83036Automatic Updater<dd><dl>
b27ce68bae92006e2ad7a9b75602c6385e529c3bAutomatic Updater<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2549269">Tools for Use With the Name Server Daemon</a></span></dt>
922312472e2e05ebc64993d465999c5351b83036Automatic Updater<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2550907">Signals</a></span></dt>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</dl></dd>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</dl>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</div>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater<p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews In this section we provide some suggested configurations along
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews with guidelines for their use. We suggest reasonable values for
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews certain option settings.
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="sect1" lang="en">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="titlepage"><div><div><h2 class="title" style="clear: both">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<a name="sample_configuration"></a>Sample Configurations</h2></div></div></div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="sect2" lang="en">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="titlepage"><div><div><h3 class="title">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<a name="id2548733"></a>A Caching-only Name Server</h3></div></div></div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews The following sample configuration is appropriate for a caching-only
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews name server for use by clients internal to a corporation. All
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews queries
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews from outside clients are refused using the <span><strong class="command">allow-query</strong></span>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews option. Alternatively, the same effect could be achieved using
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater suitable
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews firewall rules.
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater </p>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater<pre class="programlisting">
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater// Two corporate subnets we wish to allow queries from.
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updateracl corpnets { 192.168.4.0/24; 192.168.7.0/24; };
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updateroptions {
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater directory "/etc/namedb"; // Working directory
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater allow-query { corpnets; };
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater};
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater// Provide a reverse mapping for the loopback address 127.0.0.1
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updaterzone "0.0.127.in-addr.arpa" {
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater type master;
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater file "localhost.rev";
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater notify no;
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater};
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater</pre>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater</div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="sect2" lang="en">
ca67ebfe9eef0b8f04179f7e511a19e0337a5422Automatic Updater<div class="titlepage"><div><div><h3 class="title">
ca67ebfe9eef0b8f04179f7e511a19e0337a5422Automatic Updater<a name="id2548749"></a>An Authoritative-only Name Server</h3></div></div></div>
ca67ebfe9eef0b8f04179f7e511a19e0337a5422Automatic Updater<p>
ca67ebfe9eef0b8f04179f7e511a19e0337a5422Automatic Updater This sample configuration is for an authoritative-only server
ca67ebfe9eef0b8f04179f7e511a19e0337a5422Automatic Updater that is the master server for "<code class="filename">example.com</code>"
ca67ebfe9eef0b8f04179f7e511a19e0337a5422Automatic Updater and a slave for the subdomain "<code class="filename">eng.example.com</code>".
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<pre class="programlisting">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrewsoptions {
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater directory "/etc/namedb"; // Working directory
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews allow-query-cache { none; }; // Do not allow access to cache
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews allow-query { any; }; // This is the default
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews recursion no; // Do not provide recursive service
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater};
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews// Provide a reverse mapping for the loopback address 127.0.0.1
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updaterzone "0.0.127.in-addr.arpa" {
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews type master;
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater file "localhost.rev";
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews notify no;
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews};
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews// We are the master server for example.com
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrewszone "example.com" {
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater type master;
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews file "example.com.db";
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews // IP addresses of slave servers allowed to transfer example.com
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews allow-transfer {
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews 192.168.4.14;
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews 192.168.5.53;
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews };
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews};
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews// We are a slave server for eng.example.com
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrewszone "eng.example.com" {
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews type slave;
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews file "eng.example.com.bk";
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews // IP address of eng.example.com master server
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews masters { 192.168.4.12; };
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews};
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater</pre>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="sect1" lang="en">
b27ce68bae92006e2ad7a9b75602c6385e529c3bAutomatic Updater<div class="titlepage"><div><div><h2 class="title" style="clear: both">
922312472e2e05ebc64993d465999c5351b83036Automatic Updater<a name="id2548772"></a>Load Balancing</h2></div></div></div>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews A primitive form of load balancing can be achieved in
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews the <span class="acronym">DNS</span> by using multiple A records for
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews one name.
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews For example, if you have three WWW servers with network addresses
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews of 10.0.0.1, 10.0.0.2 and 10.0.0.3, a set of records such as the
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater following means that clients will connect to each machine one third
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews of the time:
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<div class="informaltable"><table border="1">
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<colgroup>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<col>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater<col>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<col>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<col>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<col>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</colgroup>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<tbody>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<tr>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews <p>
0a7ed88633a680bb881868b75ded4d09a7bbbc50Automatic Updater Name
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews <p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews TTL
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews <p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews CLASS
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews <p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews TYPE
922312472e2e05ebc64993d465999c5351b83036Automatic Updater </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews<td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews <p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews Resource Record (RR) Data
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </p>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews </td>
582f8b9a8d170a80ef67475bddb8ad5cf7cd7cadMark Andrews</tr>
922312472e2e05ebc64993d465999c5351b83036Automatic Updater<tr>
<td>
<p>
<code class="literal">www</code>
</p>
</td>
<td>
<p>
<code class="literal">600</code>
</p>
</td>
<td>
<p>
<code class="literal">IN</code>
</p>
</td>
<td>
<p>
<code class="literal">A</code>
</p>
</td>
<td>
<p>
<code class="literal">10.0.0.1</code>
</p>
</td>
</tr>
<tr>
<td>
<p></p>
</td>
<td>
<p>
<code class="literal">600</code>
</p>
</td>
<td>
<p>
<code class="literal">IN</code>
</p>
</td>
<td>
<p>
<code class="literal">A</code>
</p>
</td>
<td>
<p>
<code class="literal">10.0.0.2</code>
</p>
</td>
</tr>
<tr>
<td>
<p></p>
</td>
<td>
<p>
<code class="literal">600</code>
</p>
</td>
<td>
<p>
<code class="literal">IN</code>
</p>
</td>
<td>
<p>
<code class="literal">A</code>
</p>
</td>
<td>
<p>
<code class="literal">10.0.0.3</code>
</p>
</td>
</tr>
</tbody>
</table></div>
<p>
When a resolver queries for these records, <span class="acronym">BIND</span> 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.
</p>
<p>
For more detail on ordering responses, check the
<span><strong class="command">rrset-order</strong></span> substatement in the
<span><strong class="command">options</strong></span> statement, see
<a href="Bv9ARM.ch06.html#rrset_ordering">RRset Ordering</a>.
</p>
</div>
<div class="sect1" lang="en">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="id2549264"></a>Name Server Operations</h2></div></div></div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="id2549269"></a>Tools for Use With the Name Server Daemon</h3></div></div></div>
<p>
This section describes several indispensable diagnostic,
administrative and monitoring tools available to the system
administrator for controlling and debugging the name server
daemon.
</p>
<div class="sect3" lang="en">
<div class="titlepage"><div><div><h4 class="title">
<a name="diagnostic_tools"></a>Diagnostic Tools</h4></div></div></div>
<p>
The <span><strong class="command">dig</strong></span>, <span><strong class="command">host</strong></span>, and
<span><strong class="command">nslookup</strong></span> programs are all command
line tools
for manually querying name servers. They differ in style and
output format.
</p>
<div class="variablelist"><dl>
<dt><span class="term"><a name="dig"></a><span><strong class="command">dig</strong></span></span></dt>
<dd>
<p>
The domain information groper (<span><strong class="command">dig</strong></span>)
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.
</p>
<div class="cmdsynopsis"><p><code class="command">dig</code> [@<em class="replaceable"><code>server</code></em>] <em class="replaceable"><code>domain</code></em> [<em class="replaceable"><code>query-type</code></em>] [<em class="replaceable"><code>query-class</code></em>] [+<em class="replaceable"><code>query-option</code></em>] [-<em class="replaceable"><code>dig-option</code></em>] [%<em class="replaceable"><code>comment</code></em>]</p></div>
<p>
The usual simple use of dig will take the form
</p>
<p>
<span><strong class="command">dig @server domain query-type query-class</strong></span>
</p>
<p>
For more information and a list of available commands and
options, see the <span><strong class="command">dig</strong></span> man
page.
</p>
</dd>
<dt><span class="term"><span><strong class="command">host</strong></span></span></dt>
<dd>
<p>
The <span><strong class="command">host</strong></span> 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.
</p>
<div class="cmdsynopsis"><p><code class="command">host</code> [-aCdlrTwv] [-c <em class="replaceable"><code>class</code></em>] [-N <em class="replaceable"><code>ndots</code></em>] [-t <em class="replaceable"><code>type</code></em>] [-W <em class="replaceable"><code>timeout</code></em>] [-R <em class="replaceable"><code>retries</code></em>] <em class="replaceable"><code>hostname</code></em> [<em class="replaceable"><code>server</code></em>]</p></div>
<p>
For more information and a list of available commands and
options, see the <span><strong class="command">host</strong></span> man
page.
</p>
</dd>
<dt><span class="term"><span><strong class="command">nslookup</strong></span></span></dt>
<dd>
<p><span><strong class="command">nslookup</strong></span>
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.
</p>
<div class="cmdsynopsis"><p><code class="command">nslookup</code> [-option...] [[<em class="replaceable"><code>host-to-find</code></em>] | [- [server]]]</p></div>
<p>
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.
</p>
<p>
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.
</p>
<p>
Due to its arcane user interface and frequently inconsistent
behavior, we do not recommend the use of <span><strong class="command">nslookup</strong></span>.
Use <span><strong class="command">dig</strong></span> instead.
</p>
</dd>
</dl></div>
</div>
<div class="sect3" lang="en">
<div class="titlepage"><div><div><h4 class="title">
<a name="admin_tools"></a>Administrative Tools</h4></div></div></div>
<p>
Administrative tools play an integral part in the management
of a server.
</p>
<div class="variablelist"><dl>
<dt>
<a name="named-checkconf"></a><span class="term"><span><strong class="command">named-checkconf</strong></span></span>
</dt>
<dd>
<p>
The <span><strong class="command">named-checkconf</strong></span> program
checks the syntax of a <code class="filename">named.conf</code> file.
</p>
<div class="cmdsynopsis"><p><code class="command">named-checkconf</code> [-jvz] [-t <em class="replaceable"><code>directory</code></em>] [<em class="replaceable"><code>filename</code></em>]</p></div>
</dd>
<dt>
<a name="named-checkzone"></a><span class="term"><span><strong class="command">named-checkzone</strong></span></span>
</dt>
<dd>
<p>
The <span><strong class="command">named-checkzone</strong></span> program
checks a master file for
syntax and consistency.
</p>
<div class="cmdsynopsis"><p><code class="command">named-checkzone</code> [-djqvD] [-c <em class="replaceable"><code>class</code></em>] [-o <em class="replaceable"><code>output</code></em>] [-t <em class="replaceable"><code>directory</code></em>] [-w <em class="replaceable"><code>directory</code></em>] [-k <em class="replaceable"><code>(ignore|warn|fail)</code></em>] [-n <em class="replaceable"><code>(ignore|warn|fail)</code></em>] [-W <em class="replaceable"><code>(ignore|warn)</code></em>] <em class="replaceable"><code>zone</code></em> [<em class="replaceable"><code>filename</code></em>]</p></div>
</dd>
<dt>
<a name="named-compilezone"></a><span class="term"><span><strong class="command">named-compilezone</strong></span></span>
</dt>
<dd><p>
Similar to <span><strong class="command">named-checkzone,</strong></span> but
it always dumps the zone content to a specified file
(typically in a different format).
</p></dd>
<dt>
<a name="rndc"></a><span class="term"><span><strong class="command">rndc</strong></span></span>
</dt>
<dd>
<p>
The remote name daemon control
(<span><strong class="command">rndc</strong></span>) program allows the
system
administrator to control the operation of a name server.
If you run <span><strong class="command">rndc</strong></span> without any
options
it will display a usage message as follows:
</p>
<div class="cmdsynopsis"><p><code class="command">rndc</code> [-c <em class="replaceable"><code>config</code></em>] [-s <em class="replaceable"><code>server</code></em>] [-p <em class="replaceable"><code>port</code></em>] [-y <em class="replaceable"><code>key</code></em>] <em class="replaceable"><code>command</code></em> [<em class="replaceable"><code>command</code></em>...]</p></div>
<p>The <span><strong class="command">command</strong></span>
is one of the following:
</p>
<div class="variablelist"><dl>
<dt><span class="term"><strong class="userinput"><code>reload</code></strong></span></dt>
<dd><p>
Reload configuration file and zones.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>reload <em class="replaceable"><code>zone</code></em>
[<span class="optional"><em class="replaceable"><code>class</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span>]</code></strong></span></dt>
<dd><p>
Reload the given zone.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>refresh <em class="replaceable"><code>zone</code></em>
[<span class="optional"><em class="replaceable"><code>class</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span>]</code></strong></span></dt>
<dd><p>
Schedule zone maintenance for the given zone.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>retransfer <em class="replaceable"><code>zone</code></em>
[<span class="optional"><em class="replaceable"><code>class</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span>]</code></strong></span></dt>
<dd><p>
Retransfer the given zone from the master.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>freeze
[<span class="optional"><em class="replaceable"><code>zone</code></em>
[<span class="optional"><em class="replaceable"><code>class</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span>]</span>]</code></strong></span></dt>
<dd><p>
Suspend updates to a dynamic zone. If no zone is
specified
then all zones are suspended. This allows manual
edits to be made to a zone normally updated by dynamic
update. It
also causes changes in the journal file to be synced
into the master
and the journal file to be removed. All dynamic
update attempts will
be refused while the zone is frozen.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>thaw
[<span class="optional"><em class="replaceable"><code>zone</code></em>
[<span class="optional"><em class="replaceable"><code>class</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span>]</span>]</code></strong></span></dt>
<dd><p>
Enable updates to a frozen dynamic zone. If no zone
is
specified then all frozen zones are enabled. This
causes
the server to reload the zone from disk, and
re-enables dynamic updates
after the load has completed. After a zone is thawed,
dynamic updates
will no longer be refused.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>notify <em class="replaceable"><code>zone</code></em>
[<span class="optional"><em class="replaceable"><code>class</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span>]</code></strong></span></dt>
<dd><p>
Resend NOTIFY messages for the zone.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>reconfig</code></strong></span></dt>
<dd><p>
Reload the configuration file and load new zones,
but do not reload existing zone files even if they
have changed.
This is faster than a full <span><strong class="command">reload</strong></span> when there
is a large number of zones because it avoids the need
to examine the
modification times of the zones files.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>stats</code></strong></span></dt>
<dd><p>
Write server statistics to the statistics file.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>querylog</code></strong></span></dt>
<dd><p>
Toggle query logging. Query logging can also be enabled
by explicitly directing the <span><strong class="command">queries</strong></span>
<span><strong class="command">category</strong></span> to a
<span><strong class="command">channel</strong></span> in the
<span><strong class="command">logging</strong></span> section of
<code class="filename">named.conf</code> or by specifying
<span><strong class="command">querylog yes;</strong></span> in the
<span><strong class="command">options</strong></span> section of
<code class="filename">named.conf</code>.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>dumpdb
[<span class="optional">-all|-cache|-zone</span>]
[<span class="optional"><em class="replaceable"><code>view ...</code></em></span>]</code></strong></span></dt>
<dd><p>
Dump the server's caches (default) and / or zones to
the
dump file for the specified views. If no view is
specified all
views are dumped.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>stop [<span class="optional">-p</span>]</code></strong></span></dt>
<dd><p>
Stop the server, making sure any recent changes
made through dynamic update or IXFR are first saved to
the master files of the updated zones.
If -p is specified named's process id is returned.
This allows an external process to determine when named
had completed stopping.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>halt [<span class="optional">-p</span>]</code></strong></span></dt>
<dd><p>
Stop the server immediately. Recent changes
made through dynamic update or IXFR are not saved to
the master files, but will be rolled forward from the
journal files when the server is restarted.
If -p is specified named's process id is returned.
This allows an external process to determine when named
had completed halting.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>trace</code></strong></span></dt>
<dd><p>
Increment the servers debugging level by one.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>trace <em class="replaceable"><code>level</code></em></code></strong></span></dt>
<dd><p>
Sets the server's debugging level to an explicit
value.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>notrace</code></strong></span></dt>
<dd><p>
Sets the server's debugging level to 0.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>flush</code></strong></span></dt>
<dd><p>
Flushes the server's cache.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>flushname</code></strong> <em class="replaceable"><code>name</code></em></span></dt>
<dd><p>
Flushes the given name from the server's cache.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>status</code></strong></span></dt>
<dd><p>
Display status of the server.
Note the number of zones includes the internal <span><strong class="command">bind/CH</strong></span> zone
and the default <span><strong class="command">/IN</strong></span>
hint zone if there is not a
explicit root zone configured.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>recursing</code></strong></span></dt>
<dd><p>
Dump the list of queries named is currently recursing
on.
</p></dd>
</dl></div>
<p>
In <span class="acronym">BIND</span> 9.2, <span><strong class="command">rndc</strong></span>
supports all the commands of the BIND 8 <span><strong class="command">ndc</strong></span>
utility except <span><strong class="command">ndc start</strong></span> and
<span><strong class="command">ndc restart</strong></span>, which were also
not supported in <span><strong class="command">ndc</strong></span>'s
channel mode.
</p>
<p>
A configuration file is required, 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
<span><strong class="command">rndc</strong></span> configuration file is
<code class="filename">/etc/rndc.conf</code>, but an
alternate
location can be specified with the <code class="option">-c</code>
option. If the configuration file is not found,
<span><strong class="command">rndc</strong></span> will also look in
<code class="filename">/etc/rndc.key</code> (or whatever
<code class="varname">sysconfdir</code> was defined when
the <span class="acronym">BIND</span> build was
configured).
The <code class="filename">rndc.key</code> file is
generated by
running <span><strong class="command">rndc-confgen -a</strong></span> as
described in
<a href="Bv9ARM.ch06.html#controls_statement_definition_and_usage" title="controls Statement Definition and
Usage">the section called &#8220;<span><strong class="command">controls</strong></span> Statement Definition and
Usage&#8221;</a>.
</p>
<p>
The format of the configuration file is similar to
that of <code class="filename">named.conf</code>, but
limited to
only four statements, the <span><strong class="command">options</strong></span>,
<span><strong class="command">key</strong></span>, <span><strong class="command">server</strong></span> and
<span><strong class="command">include</strong></span>
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.
</p>
<p>
The <span><strong class="command">options</strong></span> statement has
three clauses:
<span><strong class="command">default-server</strong></span>, <span><strong class="command">default-key</strong></span>,
and <span><strong class="command">default-port</strong></span>.
<span><strong class="command">default-server</strong></span> takes a
host name or address argument and represents the server
that will
be contacted if no <code class="option">-s</code>
option is provided on the command line.
<span><strong class="command">default-key</strong></span> takes
the name of a key as its argument, as defined by a <span><strong class="command">key</strong></span> statement.
<span><strong class="command">default-port</strong></span> specifies the
port to which
<span><strong class="command">rndc</strong></span> should connect if no
port is given on the command line or in a
<span><strong class="command">server</strong></span> statement.
</p>
<p>
The <span><strong class="command">key</strong></span> statement defines an
key to be used
by <span><strong class="command">rndc</strong></span> when authenticating
with
<span><strong class="command">named</strong></span>. Its syntax is
identical to the
<span><strong class="command">key</strong></span> statement in named.conf.
The keyword <strong class="userinput"><code>key</code></strong> is
followed by a key name, which must be a valid
domain name, though it need not actually be hierarchical;
thus,
a string like "<strong class="userinput"><code>rndc_key</code></strong>" is a valid
name.
The <span><strong class="command">key</strong></span> statement has two
clauses:
<span><strong class="command">algorithm</strong></span> and <span><strong class="command">secret</strong></span>.
While the configuration parser will accept any string as the
argument
to algorithm, currently only the string "<strong class="userinput"><code>hmac-md5</code></strong>"
has any meaning. The secret is a base-64 encoded string
as specified in RFC 3548.
</p>
<p>
The <span><strong class="command">server</strong></span> statement
associates a key
defined using the <span><strong class="command">key</strong></span>
statement with a server.
The keyword <strong class="userinput"><code>server</code></strong> is followed by a
host name or address. The <span><strong class="command">server</strong></span> statement
has two clauses: <span><strong class="command">key</strong></span> and <span><strong class="command">port</strong></span>.
The <span><strong class="command">key</strong></span> clause specifies the
name of the key
to be used when communicating with this server, and the
<span><strong class="command">port</strong></span> clause can be used to
specify the port <span><strong class="command">rndc</strong></span> should
connect
to on the server.
</p>
<p>
A sample minimal configuration file is as follows:
</p>
<pre class="programlisting">
key rndc_key {
algorithm "hmac-md5";
secret "c3Ryb25nIGVub3VnaCBmb3IgYSBtYW4gYnV0IG1hZGUgZm9yIGEgd29tYW4K";
};
options {
default-server 127.0.0.1;
default-key rndc_key;
};
</pre>
<p>
This file, if installed as <code class="filename">/etc/rndc.conf</code>,
would allow the command:
</p>
<p>
<code class="prompt">$ </code><strong class="userinput"><code>rndc reload</code></strong>
</p>
<p>
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:
</p>
<pre class="programlisting">
controls {
inet 127.0.0.1 allow { localhost; } keys { rndc_key; };
};
</pre>
<p>
and it had an identical key statement for
<code class="literal">rndc_key</code>.
</p>
<p>
Running the <span><strong class="command">rndc-confgen</strong></span>
program will
conveniently create a <code class="filename">rndc.conf</code>
file for you, and also display the
corresponding <span><strong class="command">controls</strong></span>
statement that you need to
add to <code class="filename">named.conf</code>.
Alternatively,
you can run <span><strong class="command">rndc-confgen -a</strong></span>
to set up
a <code class="filename">rndc.key</code> file and not
modify
<code class="filename">named.conf</code> at all.
</p>
</dd>
</dl></div>
</div>
</div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="id2550907"></a>Signals</h3></div></div></div>
<p>
Certain UNIX signals cause the name server to take specific
actions, as described in the following table. These signals can
be sent using the <span><strong class="command">kill</strong></span> command.
</p>
<div class="informaltable"><table border="1">
<colgroup>
<col>
<col>
</colgroup>
<tbody>
<tr>
<td>
<p><span><strong class="command">SIGHUP</strong></span></p>
</td>
<td>
<p>
Causes the server to read <code class="filename">named.conf</code> and
reload the database.
</p>
</td>
</tr>
<tr>
<td>
<p><span><strong class="command">SIGTERM</strong></span></p>
</td>
<td>
<p>
Causes the server to clean up and exit.
</p>
</td>
</tr>
<tr>
<td>
<p><span><strong class="command">SIGINT</strong></span></p>
</td>
<td>
<p>
Causes the server to clean up and exit.
</p>
</td>
</tr>
</tbody>
</table></div>
</div>
</div>
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