dig.html revision b90c4f0646e61b6cc82bde5a93e400e1015974b8
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<!--
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - Copyright (C) 2004-2011, 2013, 2014 Internet Systems Consortium, Inc. ("ISC")
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - Copyright (C) 2000-2003 Internet Software Consortium.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen -
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - Permission to use, copy, modify, and/or distribute this software for any
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - purpose with or without fee is hereby granted, provided that the above
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - copyright notice and this permission notice appear in all copies.
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen -
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen - PERFORMANCE OF THIS SOFTWARE.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen-->
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen<!-- $Id$ -->
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<html>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<head>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<title>dig</title>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<meta name="generator" content="DocBook XSL Stylesheets V1.71.1">
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen</head>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<a name="man.dig"></a><div class="titlepage"></div>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<div class="refnamediv">
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<h2>Name</h2>
4e8e7a93628b4ed60aaaa47c6f72c1433f21e81dTimo Sirainen<p>dig &#8212; DNS lookup utility</p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen</div>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<div class="refsynopsisdiv">
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<h2>Synopsis</h2>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<div class="cmdsynopsis"><p><code class="command">dig</code> [@server] [<code class="option">-b <em class="replaceable"><code>address</code></em></code>] [<code class="option">-c <em class="replaceable"><code>class</code></em></code>] [<code class="option">-f <em class="replaceable"><code>filename</code></em></code>] [<code class="option">-k <em class="replaceable"><code>filename</code></em></code>] [<code class="option">-m</code>] [<code class="option">-p <em class="replaceable"><code>port#</code></em></code>] [<code class="option">-q <em class="replaceable"><code>name</code></em></code>] [<code class="option">-t <em class="replaceable"><code>type</code></em></code>] [<code class="option">-v</code>] [<code class="option">-x <em class="replaceable"><code>addr</code></em></code>] [<code class="option">-y <em class="replaceable"><code>[<span class="optional">hmac:</span>]name:key</code></em></code>] [<code class="option">-4</code>] [<code class="option">-6</code>] [name] [type] [class] [queryopt...]</p></div>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<div class="cmdsynopsis"><p><code class="command">dig</code> [<code class="option">-h</code>]</p></div>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<div class="cmdsynopsis"><p><code class="command">dig</code> [global-queryopt...] [query...]</p></div>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen</div>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<div class="refsect1" lang="en">
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<a name="id2543536"></a><h2>DESCRIPTION</h2>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<p><span><strong class="command">dig</strong></span>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen (domain information groper) is a flexible tool
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen for interrogating DNS name servers. It performs DNS lookups and
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen displays the answers that are returned from the name server(s) that
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen were queried. Most DNS administrators use <span><strong class="command">dig</strong></span> to
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen troubleshoot DNS problems because of its flexibility, ease of use and
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen clarity of output. Other lookup tools tend to have less functionality
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen than <span><strong class="command">dig</strong></span>.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen<p>
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen Although <span><strong class="command">dig</strong></span> is normally used with
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen command-line
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen arguments, it also has a batch mode of operation for reading lookup
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen requests from a file. A brief summary of its command-line arguments
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen and options is printed when the <code class="option">-h</code> option is given.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen Unlike earlier versions, the BIND 9 implementation of
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <span><strong class="command">dig</strong></span> allows multiple lookups to be issued
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen from the
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen command line.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen Unless it is told to query a specific name server,
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <span><strong class="command">dig</strong></span> will try each of the servers listed in
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <code class="filename">/etc/resolv.conf</code>. If no usable server addresses
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen are found, <span><strong class="command">dig</strong></span> will send the query to the local
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen host.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen When no command line arguments or options are given,
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <span><strong class="command">dig</strong></span> will perform an NS query for "." (the root).
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
4e8e7a93628b4ed60aaaa47c6f72c1433f21e81dTimo Sirainen<p>
4e8e7a93628b4ed60aaaa47c6f72c1433f21e81dTimo Sirainen It is possible to set per-user defaults for <span><strong class="command">dig</strong></span> via
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen <code class="filename">${HOME}/.digrc</code>. This file is read and
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen any options in it
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen are applied before the command line arguments.
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen </p>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<p>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen The IN and CH class names overlap with the IN and CH top level
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen domain names. Either use the <code class="option">-t</code> and
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen <code class="option">-c</code> options to specify the type and class,
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen use the <code class="option">-q</code> the specify the domain name, or
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen use "IN." and "CH." when looking up these top level domains.
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen </p>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen</div>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<div class="refsect1" lang="en">
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<a name="id2543614"></a><h2>SIMPLE USAGE</h2>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<p>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen A typical invocation of <span><strong class="command">dig</strong></span> looks like:
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen </p>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<pre class="programlisting"> dig @server name type </pre>
86bdb644d147a73df85abce4325254d694217a5fTimo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen where:
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen </p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<div class="variablelist"><dl>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<dt><span class="term"><code class="constant">server</code></span></dt>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<dd>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen is the name or IP address of the name server to query. This
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen can be an IPv4 address in dotted-decimal notation or an IPv6
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen address in colon-delimited notation. When the supplied
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen <em class="parameter"><code>server</code></em> argument is a hostname,
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen <span><strong class="command">dig</strong></span> resolves that name before querying
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen that name server.
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen </p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen If no <em class="parameter"><code>server</code></em> argument is
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen provided, <span><strong class="command">dig</strong></span> consults
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen <code class="filename">/etc/resolv.conf</code>; if an
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen address is found there, it queries the name server at
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen that address. If either of the <code class="option">-4</code> or
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen <code class="option">-6</code> options are in use, then
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen only addresses for the corresponding transport
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen will be tried. If no usable addresses are found,
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <span><strong class="command">dig</strong></span> will send the query to the
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen local host. The reply from the name server that
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen responds is displayed.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen</dd>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<dt><span class="term"><code class="constant">name</code></span></dt>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<dd><p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen is the name of the resource record that is to be looked up.
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen </p></dd>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<dt><span class="term"><code class="constant">type</code></span></dt>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<dd><p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen indicates what type of query is required &#8212;
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen ANY, A, MX, SIG, etc.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <em class="parameter"><code>type</code></em> can be any valid query
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen type. If no
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <em class="parameter"><code>type</code></em> argument is supplied,
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <span><strong class="command">dig</strong></span> will perform a lookup for an
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen A record.
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen </p></dd>
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen</dl></div>
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen<p>
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen </p>
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen</div>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<div class="refsect1" lang="en">
2eccb2637d0153bb7f9ad39a70f254cece74342cTimo Sirainen<a name="id2543718"></a><h2>OPTIONS</h2>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen The <code class="option">-b</code> option sets the source IP address of the query
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen to <em class="parameter"><code>address</code></em>. This must be a valid
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen address on
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen one of the host's network interfaces or "0.0.0.0" or "::". An optional
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen port
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen may be specified by appending "#&lt;port&gt;"
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen </p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen The default query class (IN for internet) is overridden by the
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <code class="option">-c</code> option. <em class="parameter"><code>class</code></em> is
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen any valid
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen class, such as HS for Hesiod records or CH for Chaosnet records.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen The <code class="option">-f</code> option makes <span><strong class="command">dig </strong></span>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen operate
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen in batch mode by reading a list of lookup requests to process from the
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen file <em class="parameter"><code>filename</code></em>. The file contains a
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen number of
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen queries, one per line. Each entry in the file should be organized in
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen the same way they would be presented as queries to
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen <span><strong class="command">dig</strong></span> using the command-line interface.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen </p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen The <code class="option">-m</code> option enables memory usage debugging.
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen
4e8e7a93628b4ed60aaaa47c6f72c1433f21e81dTimo Sirainen </p>
7877db7b5daad125b6cb3e015574f33871c9a51bTimo Sirainen<p>
ae9691f7ef36d5272d72c90fa51393dfea5dd126Timo Sirainen If a non-standard port number is to be queried, the
<code class="option">-p</code> option is used. <em class="parameter"><code>port#</code></em> is
the port number that <span><strong class="command">dig</strong></span> will send its
queries
instead of the standard DNS port number 53. This option would be used
to test a name server that has been configured to listen for queries
on a non-standard port number.
</p>
<p>
The <code class="option">-4</code> option forces <span><strong class="command">dig</strong></span>
to only
use IPv4 query transport. The <code class="option">-6</code> option forces
<span><strong class="command">dig</strong></span> to only use IPv6 query transport.
</p>
<p>
The <code class="option">-t</code> option sets the query type to
<em class="parameter"><code>type</code></em>. It can be any valid query type
which is
supported in BIND 9. The default query type is "A", unless the
<code class="option">-x</code> option is supplied to indicate a reverse lookup.
A zone transfer can be requested by specifying a type of AXFR. When
an incremental zone transfer (IXFR) is required,
<em class="parameter"><code>type</code></em> is set to <code class="literal">ixfr=N</code>.
The incremental zone transfer will contain the changes made to the zone
since the serial number in the zone's SOA record was
<em class="parameter"><code>N</code></em>.
</p>
<p>
The <code class="option">-q</code> option sets the query name to
<em class="parameter"><code>name</code></em>. This is useful to distinguish the
<em class="parameter"><code>name</code></em> from other arguments.
</p>
<p>
The <code class="option">-v</code> causes <span><strong class="command">dig</strong></span> to
print the version number and exit.
</p>
<p>
Reverse lookups &#8212; mapping addresses to names &#8212; are simplified by the
<code class="option">-x</code> option. <em class="parameter"><code>addr</code></em> is
an IPv4
address in dotted-decimal notation, or a colon-delimited IPv6 address.
When this option is used, there is no need to provide the
<em class="parameter"><code>name</code></em>, <em class="parameter"><code>class</code></em> and
<em class="parameter"><code>type</code></em> arguments. <span><strong class="command">dig</strong></span>
automatically performs a lookup for a name like
<code class="literal">11.12.13.10.in-addr.arpa</code> and sets the
query type and
class to PTR and IN respectively. By default, IPv6 addresses are
looked up using nibble format under the IP6.ARPA domain.
To use the older RFC1886 method using the IP6.INT domain
specify the <code class="option">-i</code> option. Bit string labels (RFC2874)
are now experimental and are not attempted.
</p>
<p>
To sign the DNS queries sent by <span><strong class="command">dig</strong></span> and
their
responses using transaction signatures (TSIG), specify a TSIG key file
using the <code class="option">-k</code> option. You can also specify the TSIG
key itself on the command line using the <code class="option">-y</code> option;
<em class="parameter"><code>hmac</code></em> is the type of the TSIG, default HMAC-MD5,
<em class="parameter"><code>name</code></em> is the name of the TSIG key and
<em class="parameter"><code>key</code></em> is the actual key. The key is a
base-64
encoded string, typically generated by
<span class="citerefentry"><span class="refentrytitle">dnssec-keygen</span>(8)</span>.
Caution should be taken when using the <code class="option">-y</code> option on
multi-user systems as the key can be visible in the output from
<span class="citerefentry"><span class="refentrytitle">ps</span>(1)</span>
or in the shell's history file. When
using TSIG authentication with <span><strong class="command">dig</strong></span>, the name
server that is queried needs to know the key and algorithm that is
being used. In BIND, this is done by providing appropriate
<span><strong class="command">key</strong></span> and <span><strong class="command">server</strong></span> statements in
<code class="filename">named.conf</code>.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2544009"></a><h2>QUERY OPTIONS</h2>
<p><span><strong class="command">dig</strong></span>
provides a number of query options which affect
the way in which lookups are made and the results displayed. Some of
these set or reset flag bits in the query header, some determine which
sections of the answer get printed, and others determine the timeout
and retry strategies.
</p>
<p>
Each query option is identified by a keyword preceded by a plus sign
(<code class="literal">+</code>). Some keywords set or reset an
option. These may be preceded
by the string <code class="literal">no</code> to negate the meaning of
that keyword. Other
keywords assign values to options like the timeout interval. They
have the form <code class="option">+keyword=value</code>.
The query options are:
</p>
<div class="variablelist"><dl>
<dt><span class="term"><code class="option">+[no]aaflag</code></span></dt>
<dd><p>
A synonym for <em class="parameter"><code>+[no]aaonly</code></em>.
</p></dd>
<dt><span class="term"><code class="option">+[no]aaonly</code></span></dt>
<dd><p>
Sets the "aa" flag in the query.
</p></dd>
<dt><span class="term"><code class="option">+[no]additional</code></span></dt>
<dd><p>
Display [do not display] the additional section of a
reply. The default is to display it.
</p></dd>
<dt><span class="term"><code class="option">+[no]adflag</code></span></dt>
<dd><p>
Set [do not set] the AD (authentic data) bit in the
query. This requests the server to return whether
all of the answer and authority sections have all
been validated as secure according to the security
policy of the server. AD=1 indicates that all records
have been validated as secure and the answer is not
from a OPT-OUT range. AD=0 indicate that some part
of the answer was insecure or not validated. This
bit is set by default.
</p></dd>
<dt><span class="term"><code class="option">+[no]all</code></span></dt>
<dd><p>
Set or clear all display flags.
</p></dd>
<dt><span class="term"><code class="option">+[no]answer</code></span></dt>
<dd><p>
Display [do not display] the answer section of a
reply. The default is to display it.
</p></dd>
<dt><span class="term"><code class="option">+[no]authority</code></span></dt>
<dd><p>
Display [do not display] the authority section of a
reply. The default is to display it.
</p></dd>
<dt><span class="term"><code class="option">+[no]besteffort</code></span></dt>
<dd><p>
Attempt to display the contents of messages which are
malformed. The default is to not display malformed
answers.
</p></dd>
<dt><span class="term"><code class="option">+bufsize=B</code></span></dt>
<dd><p>
Set the UDP message buffer size advertised using EDNS0
to <em class="parameter"><code>B</code></em> bytes. The maximum and
minimum sizes of this buffer are 65535 and 0 respectively.
Values outside this range are rounded up or down
appropriately. Values other than zero will cause a
EDNS query to be sent.
</p></dd>
<dt><span class="term"><code class="option">+[no]cdflag</code></span></dt>
<dd><p>
Set [do not set] the CD (checking disabled) bit in
the query. This requests the server to not perform
DNSSEC validation of responses.
</p></dd>
<dt><span class="term"><code class="option">+[no]cl</code></span></dt>
<dd><p>
Display [do not display] the CLASS when printing the
record.
</p></dd>
<dt><span class="term"><code class="option">+[no]cmd</code></span></dt>
<dd><p>
Toggles the printing of the initial comment in the
output identifying the version of <span><strong class="command">dig</strong></span>
and the query options that have been applied. This
comment is printed by default.
</p></dd>
<dt><span class="term"><code class="option">+[no]comments</code></span></dt>
<dd><p>
Toggle the display of comment lines in the output.
The default is to print comments.
</p></dd>
<dt><span class="term"><code class="option">+[no]crypto</code></span></dt>
<dd><p>
Toggle the display of cryptographic fields in DNSSEC
records. The contents of these field are unnecessary
to debug most DNSSEC validation failures and removing
them makes it easier to see the common failures. The
default is to display the fields. When omitted they
are replaced by the string "[omitted]" or in the
DNSKEY case the key id is displayed as the replacement,
e.g. "[ key id = value ]".
</p></dd>
<dt><span class="term"><code class="option">+[no]defname</code></span></dt>
<dd><p>
Deprecated, treated as a synonym for
<em class="parameter"><code>+[no]search</code></em>
</p></dd>
<dt><span class="term"><code class="option">+[no]dnssec</code></span></dt>
<dd><p>
Requests DNSSEC records be sent by setting the DNSSEC
OK bit (DO) in the OPT record in the additional section
of the query.
</p></dd>
<dt><span class="term"><code class="option">+domain=somename</code></span></dt>
<dd><p>
Set the search list to contain the single domain
<em class="parameter"><code>somename</code></em>, as if specified in
a <span><strong class="command">domain</strong></span> directive in
<code class="filename">/etc/resolv.conf</code>, and enable
search list processing as if the
<em class="parameter"><code>+search</code></em> option were given.
</p></dd>
<dt><span class="term"><code class="option">+[no]edns[=#]</code></span></dt>
<dd><p>
Specify the EDNS version to query with. Valid values
are 0 to 255. Setting the EDNS version will cause
a EDNS query to be sent. <code class="option">+noedns</code>
clears the remembered EDNS version. EDNS is set to
0 by default.
</p></dd>
<dt><span class="term"><code class="option">+[no]ednsopt[=code[:value]]</code></span></dt>
<dd><p>
Specify EDNS option with code point <code class="option">code</code>
and optionally payload of <code class="option">value</code> as a
hexadecimal string. <code class="option">+noednsopt</code>
clears the EDNS options to be sent.
</p></dd>
<dt><span class="term"><code class="option">+[no]expire</code></span></dt>
<dd><p>
Send an EDNS Expire option.
</p></dd>
<dt><span class="term"><code class="option">+[no]fail</code></span></dt>
<dd><p>
Do not try the next server if you receive a SERVFAIL.
The default is to not try the next server which is
the reverse of normal stub resolver behavior.
</p></dd>
<dt><span class="term"><code class="option">+[no]identify</code></span></dt>
<dd><p>
Show [or do not show] the IP address and port number
that supplied the answer when the
<em class="parameter"><code>+short</code></em> option is enabled. If
short form answers are requested, the default is not
to show the source address and port number of the
server that provided the answer.
</p></dd>
<dt><span class="term"><code class="option">+[no]ignore</code></span></dt>
<dd><p>
Ignore truncation in UDP responses instead of retrying
with TCP. By default, TCP retries are performed.
</p></dd>
<dt><span class="term"><code class="option">+[no]keepopen</code></span></dt>
<dd><p>
Keep the TCP socket open between queries and reuse
it rather than creating a new TCP socket for each
lookup. The default is <code class="option">+nokeepopen</code>.
</p></dd>
<dt><span class="term"><code class="option">+[no]multiline</code></span></dt>
<dd><p>
Print records like the SOA records in a verbose
multi-line format with human-readable comments. The
default is to print each record on a single line, to
facilitate machine parsing of the <span><strong class="command">dig</strong></span>
output.
</p></dd>
<dt><span class="term"><code class="option">+ndots=D</code></span></dt>
<dd><p>
Set the number of dots that have to appear in
<em class="parameter"><code>name</code></em> to <em class="parameter"><code>D</code></em>
for it to be considered absolute. The default value
is that defined using the ndots statement in
<code class="filename">/etc/resolv.conf</code>, or 1 if no
ndots statement is present. Names with fewer dots
are interpreted as relative names and will be searched
for in the domains listed in the <code class="option">search</code>
or <code class="option">domain</code> directive in
<code class="filename">/etc/resolv.conf</code>.
</p></dd>
<dt><span class="term"><code class="option">+[no]nsid</code></span></dt>
<dd><p>
Include an EDNS name server ID request when sending
a query.
</p></dd>
<dt><span class="term"><code class="option">+[no]nssearch</code></span></dt>
<dd><p>
When this option is set, <span><strong class="command">dig</strong></span>
attempts to find the authoritative name servers for
the zone containing the name being looked up and
display the SOA record that each name server has for
the zone.
</p></dd>
<dt><span class="term"><code class="option">+[no]onesoa</code></span></dt>
<dd><p>
Print only one (starting) SOA record when performing
an AXFR. The default is to print both the starting
and ending SOA records.
</p></dd>
<dt><span class="term"><code class="option">+[no]qr</code></span></dt>
<dd><p>
Print [do not print] the query as it is sent. By
default, the query is not printed.
</p></dd>
<dt><span class="term"><code class="option">+[no]question</code></span></dt>
<dd><p>
Print [do not print] the question section of a query
when an answer is returned. The default is to print
the question section as a comment.
</p></dd>
<dt><span class="term"><code class="option">+[no]recurse</code></span></dt>
<dd><p>
Toggle the setting of the RD (recursion desired) bit
in the query. This bit is set by default, which means
<span><strong class="command">dig</strong></span> normally sends recursive
queries. Recursion is automatically disabled when
the <em class="parameter"><code>+nssearch</code></em> or
<em class="parameter"><code>+trace</code></em> query options are used.
</p></dd>
<dt><span class="term"><code class="option">+retry=T</code></span></dt>
<dd><p>
Sets the number of times to retry UDP queries to
server to <em class="parameter"><code>T</code></em> instead of the
default, 2. Unlike <em class="parameter"><code>+tries</code></em>,
this does not include the initial query.
</p></dd>
<dt><span class="term"><code class="option">+[no]rrcomments</code></span></dt>
<dd><p>
Toggle the display of per-record comments in the
output (for example, human-readable key information
about DNSKEY records). The default is not to print
record comments unless multiline mode is active.
</p></dd>
<dt><span class="term"><code class="option">+[no]search</code></span></dt>
<dd><p>
Use [do not use] the search list defined by the
searchlist or domain directive in
<code class="filename">resolv.conf</code> (if any). The search
list is not used by default.
</p></dd>
<dt><span class="term"><code class="option">+[no]short</code></span></dt>
<dd><p>
Provide a terse answer. The default is to print the
answer in a verbose form.
</p></dd>
<dt><span class="term"><code class="option">+[no]showsearch</code></span></dt>
<dd><p>
Perform [do not perform] a search showing intermediate
results.
</p></dd>
<dt><span class="term"><code class="option">+[no]sigchase</code></span></dt>
<dd><p>
Chase DNSSEC signature chains. Requires dig be
compiled with -DDIG_SIGCHASE.
</p></dd>
<dt><span class="term"><code class="option">+[no]sit[<span class="optional">=####</span>]</code></span></dt>
<dd><p>
Send a Source Identity Token EDNS option, with optional
value. Replaying a SIT from a previous response will
allow the server to identify a previous client. The
default is <code class="option">+nosit</code>. Currently using
experimental value 65001 for the option code.
</p></dd>
<dt><span class="term"><code class="option">+split=W</code></span></dt>
<dd><p>
Split long hex- or base64-formatted fields in resource
records into chunks of <em class="parameter"><code>W</code></em>
characters (where <em class="parameter"><code>W</code></em> is rounded
up to the nearest multiple of 4).
<em class="parameter"><code>+nosplit</code></em> or
<em class="parameter"><code>+split=0</code></em> causes fields not to
be split at all. The default is 56 characters, or
44 characters when multiline mode is active.
</p></dd>
<dt><span class="term"><code class="option">+[no]stats</code></span></dt>
<dd><p>
This query option toggles the printing of statistics:
when the query was made, the size of the reply and
so on. The default behavior is to print the query
statistics.
</p></dd>
<dt><span class="term"><code class="option">+[no]subnet=addr/prefix</code></span></dt>
<dd><p>
Send an EDNS Client Subnet option with the speciifed
IP address or network prefix.
</p></dd>
<dt><span class="term"><code class="option">+[no]tcp</code></span></dt>
<dd><p>
Use [do not use] TCP when querying name servers. The
default behavior is to use UDP unless an
<code class="literal">ixfr=N</code> query is requested, in which
case the default is TCP. AXFR queries always use
TCP.
</p></dd>
<dt><span class="term"><code class="option">+time=T</code></span></dt>
<dd><p>
Sets the timeout for a query to
<em class="parameter"><code>T</code></em> seconds. The default
timeout is 5 seconds.
An attempt to set <em class="parameter"><code>T</code></em> to less
than 1 will result
in a query timeout of 1 second being applied.
</p></dd>
<dt><span class="term"><code class="option">+[no]topdown</code></span></dt>
<dd><p>
When chasing DNSSEC signature chains perform a top-down
validation. Requires dig be compiled with -DDIG_SIGCHASE.
</p></dd>
<dt><span class="term"><code class="option">+[no]trace</code></span></dt>
<dd>
<p>
Toggle tracing of the delegation path from the root
name servers for the name being looked up. Tracing
is disabled by default. When tracing is enabled,
<span><strong class="command">dig</strong></span> makes iterative queries to
resolve the name being looked up. It will follow
referrals from the root servers, showing the answer
from each server that was used to resolve the lookup.
</p>
<p>
<span><strong class="command">+dnssec</strong></span> is also set when +trace
is set to better emulate the default queries from a
nameserver.
</p>
</dd>
<dt><span class="term"><code class="option">+tries=T</code></span></dt>
<dd><p>
Sets the number of times to try UDP queries to server
to <em class="parameter"><code>T</code></em> instead of the default,
3. If <em class="parameter"><code>T</code></em> is less than or equal
to zero, the number of tries is silently rounded up
to 1.
</p></dd>
<dt><span class="term"><code class="option">+trusted-key=####</code></span></dt>
<dd>
<p>
Specifies a file containing trusted keys to be used
with <code class="option">+sigchase</code>. Each DNSKEY record
must be on its own line.
</p>
<p>
If not specified, <span><strong class="command">dig</strong></span> will look
for <code class="filename">/etc/trusted-key.key</code> then
<code class="filename">trusted-key.key</code> in the current
directory.
</p>
<p>
Requires dig be compiled with -DDIG_SIGCHASE.
</p>
</dd>
<dt><span class="term"><code class="option">+[no]ttlid</code></span></dt>
<dd><p>
Display [do not display] the TTL when printing the
record.
</p></dd>
<dt><span class="term"><code class="option">+[no]ttlunits</code></span></dt>
<dd><p>
Display [do not display] the TTL in friendly human-readable
time units of "s", "m", "h", "d", and "w", representing
seconds, minutes, hours, days and weeks. Implies +ttlid.
</p></dd>
<dt><span class="term"><code class="option">+[no]vc</code></span></dt>
<dd><p>
Use [do not use] TCP when querying name servers. This
alternate syntax to <em class="parameter"><code>+[no]tcp</code></em>
is provided for backwards compatibility. The "vc"
stands for "virtual circuit".
</p></dd>
</dl></div>
<p>
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2545262"></a><h2>MULTIPLE QUERIES</h2>
<p>
The BIND 9 implementation of <span><strong class="command">dig </strong></span>
supports
specifying multiple queries on the command line (in addition to
supporting the <code class="option">-f</code> batch file option). Each of those
queries can be supplied with its own set of flags, options and query
options.
</p>
<p>
In this case, each <em class="parameter"><code>query</code></em> argument
represent an
individual query in the command-line syntax described above. Each
consists of any of the standard options and flags, the name to be
looked up, an optional query type and class and any query options that
should be applied to that query.
</p>
<p>
A global set of query options, which should be applied to all queries,
can also be supplied. These global query options must precede the
first tuple of name, class, type, options, flags, and query options
supplied on the command line. Any global query options (except
the <code class="option">+[no]cmd</code> option) can be
overridden by a query-specific set of query options. For example:
</p>
<pre class="programlisting">
dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr
</pre>
<p>
shows how <span><strong class="command">dig</strong></span> could be used from the
command line
to make three lookups: an ANY query for <code class="literal">www.isc.org</code>, a
reverse lookup of 127.0.0.1 and a query for the NS records of
<code class="literal">isc.org</code>.
A global query option of <em class="parameter"><code>+qr</code></em> is
applied, so
that <span><strong class="command">dig</strong></span> shows the initial query it made
for each
lookup. The final query has a local query option of
<em class="parameter"><code>+noqr</code></em> which means that <span><strong class="command">dig</strong></span>
will not print the initial query when it looks up the NS records for
<code class="literal">isc.org</code>.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2545324"></a><h2>IDN SUPPORT</h2>
<p>
If <span><strong class="command">dig</strong></span> has been built with IDN (internationalized
domain name) support, it can accept and display non-ASCII domain names.
<span><strong class="command">dig</strong></span> appropriately converts character encoding of
domain name before sending a request to DNS server or displaying a
reply from the server.
If you'd like to turn off the IDN support for some reason, defines
the <code class="envar">IDN_DISABLE</code> environment variable.
The IDN support is disabled if the variable is set when
<span><strong class="command">dig</strong></span> runs.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2545347"></a><h2>FILES</h2>
<p><code class="filename">/etc/resolv.conf</code>
</p>
<p><code class="filename">${HOME}/.digrc</code>
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2545364"></a><h2>SEE ALSO</h2>
<p><span class="citerefentry"><span class="refentrytitle">host</span>(1)</span>,
<span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>,
<span class="citerefentry"><span class="refentrytitle">dnssec-keygen</span>(8)</span>,
<em class="citetitle">RFC1035</em>.
</p>
</div>
<div class="refsect1" lang="en">
<a name="id2545401"></a><h2>BUGS</h2>
<p>
There are probably too many query options.
</p>
</div>
</div></body>
</html>