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1382N/A<title>Chapter�3.�Name Server Configuration</title>
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1393N/A<tr><th colspan="3" align="center">Chapter�3.�Name Server Configuration</th></tr>
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1399N/A</div>
1399N/A<div class="chapter" lang="en">
1399N/A<div class="titlepage"><div><div><h2 class="title">
1393N/A<a name="Bv9ARM.ch03"></a>Chapter�3.�Name Server Configuration</h2></div></div></div>
1393N/A<div class="toc">
1399N/A<p><b>Table of Contents</b></p>
1393N/A<dl>
1393N/A<dt><span class="sect1"><a href="Bv9ARM.ch03.html#sample_configuration">Sample Configurations</a></span></dt>
1393N/A<dd><dl>
1393N/A<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2567774">A Caching-only Name Server</a></span></dt>
1393N/A<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2567995">An Authoritative-only Name Server</a></span></dt>
1393N/A</dl></dd>
1393N/A<dt><span class="sect1"><a href="Bv9ARM.ch03.html#id2568018">Load Balancing</a></span></dt>
1393N/A<dt><span class="sect1"><a href="Bv9ARM.ch03.html#id2568372">Name Server Operations</a></span></dt>
1393N/A<dd><dl>
1393N/A<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2568377">Tools for Use With the Name Server Daemon</a></span></dt>
1393N/A<dt><span class="sect2"><a href="Bv9ARM.ch03.html#id2570695">Signals</a></span></dt>
1393N/A</dl></dd>
1393N/A</dl>
1393N/A</div>
1393N/A<p>
1393N/A In this chapter we provide some suggested configurations along
1393N/A with guidelines for their use. We suggest reasonable values for
1393N/A certain option settings.
1393N/A </p>
1393N/A<div class="sect1" lang="en">
1393N/A<div class="titlepage"><div><div><h2 class="title" style="clear: both">
1393N/A<a name="sample_configuration"></a>Sample Configurations</h2></div></div></div>
1393N/A<div class="sect2" lang="en">
1393N/A<div class="titlepage"><div><div><h3 class="title">
1393N/A<a name="id2567774"></a>A Caching-only Name Server</h3></div></div></div>
1393N/A<p>
1393N/A The following sample configuration is appropriate for a caching-only
1393N/A name server for use by clients internal to a corporation. All
1393N/A queries
1393N/A from outside clients are refused using the <span><strong class="command">allow-query</strong></span>
1393N/A option. Alternatively, the same effect could be achieved using
1393N/A suitable
1393N/A firewall rules.
1393N/A </p>
1393N/A<pre class="programlisting">
1393N/A// Two corporate subnets we wish to allow queries from.
1393N/Aacl corpnets { 192.168.4.0/24; 192.168.7.0/24; };
1393N/Aoptions {
1393N/A // Working directory
1382N/A directory "/etc/namedb";
1382N/A
allow-query { corpnets; };
};
// Provide a reverse mapping for the loopback
// address 127.0.0.1
zone "0.0.127.in-addr.arpa" {
type master;
file "localhost.rev";
notify no;
};
</pre>
</div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="id2567995"></a>An Authoritative-only Name Server</h3></div></div></div>
<p>
This sample configuration is for an authoritative-only server
that is the master server for "<code class="filename">example.com</code>"
and a slave for the subdomain "<code class="filename">eng.example.com</code>".
</p>
<pre class="programlisting">
options {
// Working directory
directory "/etc/namedb";
// Do not allow access to cache
allow-query-cache { none; };
// This is the default
allow-query { any; };
// Do not provide recursive service
recursion no;
};
// Provide a reverse mapping for the loopback
// address 127.0.0.1
zone "0.0.127.in-addr.arpa" {
type master;
file "localhost.rev";
notify no;
};
// We are the master server for example.com
zone "example.com" {
type master;
file "example.com.db";
// IP addresses of slave servers allowed to
// transfer example.com
allow-transfer {
192.168.4.14;
192.168.5.53;
};
};
// We are a slave server for eng.example.com
zone "eng.example.com" {
type slave;
file "eng.example.com.bk";
// IP address of eng.example.com master server
masters { 192.168.4.12; };
};
</pre>
</div>
</div>
<div class="sect1" lang="en">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="id2568018"></a>Load Balancing</h2></div></div></div>
<p>
A primitive form of load balancing can be achieved in
the <acronym class="acronym">DNS</acronym> by using multiple records
(such as multiple A records) for one name.
</p>
<p>
For example, if you have three WWW servers with network addresses
of 10.0.0.1, 10.0.0.2 and 10.0.0.3, a set of records such as the
following means that clients will connect to each machine one third
of the time:
</p>
<div class="informaltable"><table border="1">
<colgroup>
<col>
<col>
<col>
<col>
<col>
</colgroup>
<tbody>
<tr>
<td>
<p>
Name
</p>
</td>
<td>
<p>
TTL
</p>
</td>
<td>
<p>
CLASS
</p>
</td>
<td>
<p>
TYPE
</p>
</td>
<td>
<p>
Resource Record (RR) Data
</p>
</td>
</tr>
<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, <acronym class="acronym">BIND</acronym> 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> sub-statement 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="id2568372"></a>Name Server Operations</h2></div></div></div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="id2568377"></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 <span><strong class="command">dig</strong></span> 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> [-aCdlnrsTwv] [-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>] [-m <em class="replaceable"><code>flag</code></em>] [-4] [-6] <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.
Since <acronym class="acronym">BIND</acronym> 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.
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>sign <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>
Fetch all DNSSEC keys for the given zone
from the key directory (see
<span><strong class="command">key-directory</strong></span> in
<a href="Bv9ARM.ch06.html#options" title="options Statement Definition and
Usage">the section called &#8220;<span><strong class="command">options</strong></span> Statement Definition and
Usage&#8221;</a>). If they are within
their publication period, merge them into the
zone's DNSKEY RRset. If the DNSKEY RRset
is changed, then the zone is automatically
re-signed with the new key set.
</p>
<p>
This command requires that the
<span><strong class="command">auto-dnssec</strong></span> zone option be set
to <code class="literal">allow</code> or
<code class="literal">maintain</code>,
and also requires the zone to be configured to
allow dynamic DNS.
See <a href="Bv9ARM.ch06.html#dynamic_update_policies" title="Dynamic Update Policies">the section called &#8220;Dynamic Update Policies&#8221;</a> for
more details.
</p>
</dd>
<dt><span class="term"><strong class="userinput"><code>loadkeys <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>
Fetch all DNSSEC keys for the given zone
from the key directory (see
<span><strong class="command">key-directory</strong></span> in
<a href="Bv9ARM.ch06.html#options" title="options Statement Definition and
Usage">the section called &#8220;<span><strong class="command">options</strong></span> Statement Definition and
Usage&#8221;</a>). If they are within
their publication period, merge them into the
zone's DNSKEY RRset. Unlike <span><strong class="command">rndc
sign</strong></span>, however, the zone is not
immediately re-signed by the new keys, but is
allowed to incrementally re-sign over time.
</p>
<p>
This command requires that the
<span><strong class="command">auto-dnssec</strong></span> zone option
be set to <code class="literal">maintain</code>,
and also requires the zone to be configured to
allow dynamic DNS.
See <a href="Bv9ARM.ch06.html#dynamic_update_policies" title="Dynamic Update Policies">the section called &#8220;Dynamic Update Policies&#8221;</a> for
more details.
</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 file.
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. If
the zone has changed and the
<span><strong class="command">ixfr-from-differences</strong></span> option is
in use, then the journal file will be updated to
reflect changes in the zone. Otherwise, if the
zone has changed, any existing journal file will be
removed.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>sync
[<span class="optional">-clean</span>]
[<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>
Sync changes in the journal file for a dynamic zone
to the master file. If the "-clean" option is
specified, the journal file is also removed. If
no zone is specified, then all zones are synced.
</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>zonestatus
[<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>
Displays the current status of the given zone,
including the master file name and any include
files from which it was loaded, when it was most
recently loaded, the current serial number, the
number of nodes, whether the zone supports
dynamic updates, whether the zone is DNSSEC
signed, whether it uses automatic DNSSEC key
management or inline signing, and the scheduled
refresh or expiry times for the zone.
</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 class="optional">on|off</span>]
</span></dt>
<dd>
<p>
Enable or disable query logging. (For backward
compatibility, this command can also be used without
an argument to toggle query logging on and off.)
</p>
<p>
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>secroots
[<span class="optional"><em class="replaceable"><code>view ...</code></em></span>]</code></strong></span></dt>
<dd><p>
Dump the server's security roots to the secroots
file for the specified views. If no view is
specified, security roots for 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 <code class="option">-p</code> is specified <span><strong class="command">named</strong></span>'s process id is returned.
This allows an external process to determine when <span><strong class="command">named</strong></span>
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 <code class="option">-p</code> is specified <span><strong class="command">named</strong></span>'s process id is returned.
This allows an external process to determine when <span><strong class="command">named</strong></span>
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 class="optional"><em class="replaceable"><code>view</code></em></span>]
</span></dt>
<dd><p>
Flushes the given name from the server's DNS cache,
and from the server's nameserver address database
if applicable.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>flushtree</code></strong>
<em class="replaceable"><code>name</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]
</span></dt>
<dd><p>
Flushes the given name, and all of its subdomains,
from the server's DNS cache. (The server's
nameserver address database is not affected.)
</p></dd>
<dt><span class="term"><strong class="userinput"><code>status</code></strong></span></dt>
<dd><p>
Display status of the server.
Note that 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 an
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 <span><strong class="command">named</strong></span> is currently recursing
on.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>validation
[<span class="optional">on|off</span>]
[<span class="optional"><em class="replaceable"><code>view ...</code></em></span>]
</code></strong></span></dt>
<dd><p>
Enable or disable DNSSEC validation.
Note <span><strong class="command">dnssec-enable</strong></span> also needs to be
set to <strong class="userinput"><code>yes</code></strong> to be effective.
It defaults to enabled.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>tsig-list</code></strong></span></dt>
<dd><p>
List the names of all TSIG keys currently configured
for use by <span><strong class="command">named</strong></span> in each view. The
list both statically configured keys and dynamic
TKEY-negotiated keys.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>tsig-delete</code></strong>
<em class="replaceable"><code>keyname</code></em>
[<span class="optional"><em class="replaceable"><code>view</code></em></span>]</span></dt>
<dd><p>
Delete a given TKEY-negotiated key from the server.
(This does not apply to statically configured TSIG
keys.)
</p></dd>
<dt><span class="term"><strong class="userinput"><code>addzone
<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>]
<em class="replaceable"><code>configuration</code></em>
</code></strong></span></dt>
<dd>
<p>
Add a zone while the server is running. This
command requires the
<span><strong class="command">allow-new-zones</strong></span> option to be set
to <strong class="userinput"><code>yes</code></strong>. The
<em class="replaceable"><code>configuration</code></em> string
specified on the command line is the zone
configuration text that would ordinarily be
placed in <code class="filename">named.conf</code>.
</p>
<p>
The configuration is saved in a file called
<code class="filename"><em class="replaceable"><code>hash</code></em>.nzf</code>,
where <em class="replaceable"><code>hash</code></em> is a
cryptographic hash generated from the name of
the view. When <span><strong class="command">named</strong></span> is
restarted, the file will be loaded into the view
configuration, so that zones that were added
can persist after a restart.
</p>
<p>
This sample <span><strong class="command">addzone</strong></span> command
would add the zone <code class="literal">example.com</code>
to the default view:
</p>
<p>
<code class="prompt">$ </code><strong class="userinput"><code>rndc addzone example.com '{ type master; file "example.com.db"; };'</code></strong>
</p>
<p>
(Note the brackets and semi-colon around the zone
configuration text.)
</p>
</dd>
<dt><span class="term"><strong class="userinput"><code>delzone
<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>
Delete a zone while the server is running.
Only zones that were originally added via
<span><strong class="command">rndc addzone</strong></span> can be deleted
in this matter.
</p></dd>
<dt><span class="term"><strong class="userinput"><code>signing
[<span class="optional">( -list | -clear <em class="replaceable"><code>keyid/algorithm</code></em> | -clear <code class="literal">all</code> | -nsec3param ( <em class="replaceable"><code>parameters</code></em> | <code class="literal">none</code> ) ) </span>]
<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>
List, edit, or remove the DNSSEC signing state for
the specified zone. The status of ongoing DNSSEC
operations (such as signing or generating
NSEC3 chains) is stored in the zone in the form
of DNS resource records of type
<span><strong class="command">sig-signing-type</strong></span>.
<span><strong class="command">rndc signing -list</strong></span> converts
these records into a human-readable form,
indicating which keys are currently signing
or have finished signing the zone, and which NSEC3
NSEC3 chains are being created or removed.
</p>
<p>
<span><strong class="command">rndc signing -clear</strong></span> can remove
a single key (specified in the same format that
<span><strong class="command">rndc signing -list</strong></span> uses to
display it), or all keys. In either case, only
completed keys are removed; any record indicating
that a key has not yet finished signing the zone
will be retained.
</p>
<p>
<span><strong class="command">rndc signing -nsec3param</strong></span> sets
the NSEC3 parameters for a zone. This is the
only supported mechanism for using NSEC3 with
<span><strong class="command">inline-signing</strong></span> zones.
Parameters are specified in the same format as
an NSEC3PARAM resource record: hash algorithm,
flags, iterations, and salt, in that order.
</p>
<p>
Currently, the only defined value for hash algorithm
is <code class="literal">1</code>, representing SHA-1.
The <code class="option">flags</code> may be set to
<code class="literal">0</code> or <code class="literal">1</code>,
depending on whether you wish to set the opt-out
bit in the NSEC3 chain. <code class="option">iterations</code>
defines the number of additional times to apply
the algorithm when generating an NSEC3 hash. The
<code class="option">salt</code> is a string of data expressed
in hexidecimal, or a hyphen (`-') if no salt is
to be used.
</p>
<p>
So, for example, to create an NSEC3 chain using
the SHA-1 hash algorithm, no opt-out flag,
10 iterations, and a salt value of "FFFF", use:
<span><strong class="command">rndc signing -nsec3param 1 0 10 FFFF &lt;zone&gt;</strong></span>.
To set the opt-out flag, 15 iterations, and no
salt, use:
<span><strong class="command">rndc signing -nsec3param 1 1 15 - &lt;zone&gt;</strong></span>.
</p>
<p>
<span><strong class="command">rndc signing -nsec3param none</strong></span>
removes an existing NSEC3 chain and replaces it
with NSEC.
</p>
</dd>
</dl></div>
<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 <acronym class="acronym">BIND</acronym> 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 a
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 <code class="filename">named.conf</code>.
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="id2570695"></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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