1062 lines
39 KiB
Python
1062 lines
39 KiB
Python
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<!--
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- Copyright (C) 2000-2011, 2013-2018 Internet Systems Consortium, Inc. ("ISC")
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-
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- This Source Code Form is subject to the terms of the Mozilla Public
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- License, v. 2.0. If a copy of the MPL was not distributed with this
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- file, You can obtain one at http://mozilla.org/MPL/2.0/.
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-->
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<html lang="en">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
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<title>dig</title>
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<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
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</head>
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<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry">
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<a name="man.dig"></a><div class="titlepage"></div>
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<div class="refnamediv">
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<h2>Name</h2>
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<p>
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dig
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— DNS lookup utility
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</p>
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</div>
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<div class="refsynopsisdiv">
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<h2>Synopsis</h2>
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<div class="cmdsynopsis"><p>
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<code class="command">dig</code>
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[@server]
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[<code class="option">-b <em class="replaceable"><code>address</code></em></code>]
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[<code class="option">-c <em class="replaceable"><code>class</code></em></code>]
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[<code class="option">-f <em class="replaceable"><code>filename</code></em></code>]
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[<code class="option">-k <em class="replaceable"><code>filename</code></em></code>]
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[<code class="option">-m</code>]
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[<code class="option">-p <em class="replaceable"><code>port#</code></em></code>]
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[<code class="option">-q <em class="replaceable"><code>name</code></em></code>]
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[<code class="option">-t <em class="replaceable"><code>type</code></em></code>]
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[<code class="option">-v</code>]
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[<code class="option">-x <em class="replaceable"><code>addr</code></em></code>]
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[<code class="option">-y <em class="replaceable"><code>[<span class="optional">hmac:</span>]name:key</code></em></code>]
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[
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[<code class="option">-4</code>]
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| [<code class="option">-6</code>]
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]
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[name]
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[type]
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[class]
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[queryopt...]
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</p></div>
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<div class="cmdsynopsis"><p>
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<code class="command">dig</code>
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[<code class="option">-h</code>]
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</p></div>
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<div class="cmdsynopsis"><p>
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<code class="command">dig</code>
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[global-queryopt...]
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[query...]
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</p></div>
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</div>
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<div class="refsection">
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<a name="id-1.7"></a><h2>DESCRIPTION</h2>
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<p><span class="command"><strong>dig</strong></span> is a flexible tool
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for interrogating DNS name servers. It performs DNS lookups and
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displays the answers that are returned from the name server(s) that
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were queried. Most DNS administrators use <span class="command"><strong>dig</strong></span> to
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troubleshoot DNS problems because of its flexibility, ease of use and
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clarity of output. Other lookup tools tend to have less functionality
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than <span class="command"><strong>dig</strong></span>.
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</p>
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<p>
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Although <span class="command"><strong>dig</strong></span> is normally used with
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command-line
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arguments, it also has a batch mode of operation for reading lookup
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requests from a file. A brief summary of its command-line arguments
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and options is printed when the <code class="option">-h</code> option is given.
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Unlike earlier versions, the BIND 9 implementation of
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<span class="command"><strong>dig</strong></span> allows multiple lookups to be issued
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from the
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command line.
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</p>
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<p>
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Unless it is told to query a specific name server,
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<span class="command"><strong>dig</strong></span> will try each of the servers listed in
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<code class="filename">/etc/resolv.conf</code>. If no usable server addresses
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are found, <span class="command"><strong>dig</strong></span> will send the query to the local
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host.
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</p>
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<p>
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When no command line arguments or options are given,
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<span class="command"><strong>dig</strong></span> will perform an NS query for "." (the root).
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</p>
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<p>
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It is possible to set per-user defaults for <span class="command"><strong>dig</strong></span> via
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<code class="filename">${HOME}/.digrc</code>. This file is read and
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any options in it
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are applied before the command line arguments.
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</p>
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<p>
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The IN and CH class names overlap with the IN and CH top level
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domain names. Either use the <code class="option">-t</code> and
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<code class="option">-c</code> options to specify the type and class,
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use the <code class="option">-q</code> the specify the domain name, or
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use "IN." and "CH." when looking up these top level domains.
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</p>
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</div>
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<div class="refsection">
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<a name="id-1.8"></a><h2>SIMPLE USAGE</h2>
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<p>
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A typical invocation of <span class="command"><strong>dig</strong></span> looks like:
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</p>
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<pre class="programlisting"> dig @server name type </pre>
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<p>
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where:
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</p>
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<div class="variablelist"><dl class="variablelist">
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<dt><span class="term"><code class="constant">server</code></span></dt>
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<dd>
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<p>
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is the name or IP address of the name server to query. This
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can be an IPv4 address in dotted-decimal notation or an IPv6
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address in colon-delimited notation. When the supplied
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<em class="parameter"><code>server</code></em> argument is a hostname,
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<span class="command"><strong>dig</strong></span> resolves that name before querying
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that name server.
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</p>
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<p>
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If no <em class="parameter"><code>server</code></em> argument is
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provided, <span class="command"><strong>dig</strong></span> consults
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<code class="filename">/etc/resolv.conf</code>; if an
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address is found there, it queries the name server at
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that address. If either of the <code class="option">-4</code> or
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<code class="option">-6</code> options are in use, then
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only addresses for the corresponding transport
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will be tried. If no usable addresses are found,
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<span class="command"><strong>dig</strong></span> will send the query to the
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local host. The reply from the name server that
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responds is displayed.
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</p>
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</dd>
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<dt><span class="term"><code class="constant">name</code></span></dt>
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<dd>
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<p>
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is the name of the resource record that is to be looked up.
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</p>
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</dd>
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<dt><span class="term"><code class="constant">type</code></span></dt>
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<dd>
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<p>
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indicates what type of query is required —
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ANY, A, MX, SIG, etc.
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<em class="parameter"><code>type</code></em> can be any valid query
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type. If no
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<em class="parameter"><code>type</code></em> argument is supplied,
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<span class="command"><strong>dig</strong></span> will perform a lookup for an
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A record.
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</p>
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</dd>
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</dl></div>
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<p>
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</p>
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</div>
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<div class="refsection">
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<a name="id-1.9"></a><h2>OPTIONS</h2>
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<div class="variablelist"><dl class="variablelist">
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<dt><span class="term">-4</span></dt>
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<dd>
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<p>
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Use IPv4 only.
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</p>
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</dd>
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<dt><span class="term">-6</span></dt>
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<dd>
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<p>
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Use IPv6 only.
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</p>
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</dd>
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<dt><span class="term">-b <em class="replaceable"><code>address[<span class="optional">#port</span>]</code></em></span></dt>
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<dd>
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<p>
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Set the source IP address of the query.
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The <em class="parameter"><code>address</code></em> must be a valid address on
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one of the host's network interfaces, or "0.0.0.0" or "::". An
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optional port may be specified by appending "#<port>"
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</p>
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</dd>
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<dt><span class="term">-c <em class="replaceable"><code>class</code></em></span></dt>
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<dd>
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<p>
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Set the query class. The
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default <em class="parameter"><code>class</code></em> is IN; other classes
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are HS for Hesiod records or CH for Chaosnet records.
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</p>
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</dd>
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<dt><span class="term">-f <em class="replaceable"><code>file</code></em></span></dt>
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<dd>
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<p>
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Batch mode: <span class="command"><strong>dig</strong></span> reads a list of lookup
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requests to process from the
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given <em class="parameter"><code>file</code></em>. Each line in the file
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should be organized in the same way they would be
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presented as queries to
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<span class="command"><strong>dig</strong></span> using the command-line interface.
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</p>
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</dd>
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<dt><span class="term">-i</span></dt>
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<dd>
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<p>
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Do reverse IPv6 lookups using the obsolete RFC1886 IP6.INT
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domain, which is no longer in use. Obsolete bit string
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label queries (RFC2874) are not attempted.
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</p>
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</dd>
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<dt><span class="term">-k <em class="replaceable"><code>keyfile</code></em></span></dt>
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<dd>
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<p>
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Sign queries using TSIG using a key read from the given file.
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Key files can be generated using
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<span class="citerefentry">
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<span class="refentrytitle">tsig-keygen</span>(8)
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</span>.
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When using TSIG authentication with <span class="command"><strong>dig</strong></span>,
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the name server that is queried needs to know the key and
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algorithm that is being used. In BIND, this is done by
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providing appropriate <span class="command"><strong>key</strong></span>
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and <span class="command"><strong>server</strong></span> statements in
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<code class="filename">named.conf</code>.
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</p>
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</dd>
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<dt><span class="term">-m</span></dt>
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<dd>
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<p>
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Enable memory usage debugging.
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</p>
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</dd>
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<dt><span class="term">-p <em class="replaceable"><code>port</code></em></span></dt>
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<dd>
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<p>
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Send the query to a non-standard port on the server,
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instead of the default port 53. This option would be used
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to test a name server that has been configured to listen
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for queries on a non-standard port number.
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</p>
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</dd>
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<dt><span class="term">-q <em class="replaceable"><code>name</code></em></span></dt>
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<dd>
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<p>
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The domain name to query. This is useful to distinguish
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the <em class="parameter"><code>name</code></em> from other arguments.
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</p>
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</dd>
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<dt><span class="term">-t <em class="replaceable"><code>type</code></em></span></dt>
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<dd>
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<p>
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The resource record type to query. It can be any valid query type
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which is
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supported in BIND 9. The default query type is "A", unless the
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<code class="option">-x</code> option is supplied to indicate a reverse lookup.
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A zone transfer can be requested by specifying a type of AXFR. When
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an incremental zone transfer (IXFR) is required, set the
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<em class="parameter"><code>type</code></em> to <code class="literal">ixfr=N</code>.
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The incremental zone transfer will contain the changes
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made to the zone since the serial number in the zone's SOA
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record was
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<em class="parameter"><code>N</code></em>.
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</p>
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</dd>
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<dt><span class="term">-u</span></dt>
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<dd>
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<p>
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Print query times in microseconds instead of milliseconds.
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</p>
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</dd>
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<dt><span class="term">-v</span></dt>
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<dd>
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<p>
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Print the version number and exit.
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</p>
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</dd>
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<dt><span class="term">-x <em class="replaceable"><code>addr</code></em></span></dt>
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<dd>
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<p>
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Simplified reverse lookups, for mapping addresses to
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names. The <em class="parameter"><code>addr</code></em> is an IPv4 address
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in dotted-decimal notation, or a colon-delimited IPv6
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address. When the <code class="option">-x</code> is used, there is no
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need to provide
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the <em class="parameter"><code>name</code></em>, <em class="parameter"><code>class</code></em>
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and <em class="parameter"><code>type</code></em>
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arguments. <span class="command"><strong>dig</strong></span> automatically performs a
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lookup for a name like
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<code class="literal">94.2.0.192.in-addr.arpa</code> and sets the
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query type and class to PTR and IN respectively. IPv6
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addresses are looked up using nibble format under the
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IP6.ARPA domain (but see also the <code class="option">-i</code>
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option).
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</p>
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</dd>
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<dt><span class="term">-y <em class="replaceable"><code>[<span class="optional">hmac:</span>]keyname:secret</code></em></span></dt>
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<dd>
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<p>
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Sign queries using TSIG with the given authentication key.
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<em class="parameter"><code>keyname</code></em> is the name of the key, and
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<em class="parameter"><code>secret</code></em> is the base64 encoded shared secret.
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<em class="parameter"><code>hmac</code></em> is the name of the key algorithm;
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valid choices are <code class="literal">hmac-md5</code>,
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<code class="literal">hmac-sha1</code>, <code class="literal">hmac-sha224</code>,
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<code class="literal">hmac-sha256</code>, <code class="literal">hmac-sha384</code>, or
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<code class="literal">hmac-sha512</code>. If <em class="parameter"><code>hmac</code></em>
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is not specified, the default is <code class="literal">hmac-md5</code>
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or if MD5 was disabled <code class="literal">hmac-sha256</code>.
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</p>
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<p>
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NOTE: You should use the <code class="option">-k</code> option and
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avoid the <code class="option">-y</code> option, because
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with <code class="option">-y</code> the shared secret is supplied as
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a command line argument in clear text. This may be visible
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in the output from
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<span class="citerefentry">
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<span class="refentrytitle">ps</span>(1)
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</span>
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or in a history file maintained by the user's shell.
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</p>
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</dd>
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</dl></div>
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</div>
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<div class="refsection">
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<a name="id-1.10"></a><h2>QUERY OPTIONS</h2>
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<p><span class="command"><strong>dig</strong></span>
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provides a number of query options which affect
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the way in which lookups are made and the results displayed. Some of
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these set or reset flag bits in the query header, some determine which
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sections of the answer get printed, and others determine the timeout
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and retry strategies.
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</p>
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<p>
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Each query option is identified by a keyword preceded by a plus sign
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(<code class="literal">+</code>). Some keywords set or reset an
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option. These may be preceded
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by the string <code class="literal">no</code> to negate the meaning of
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that keyword. Other
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keywords assign values to options like the timeout interval. They
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have the form <code class="option">+keyword=value</code>.
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Keywords may be abbreviated, provided the abbreviation is
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unambiguous; for example, <code class="literal">+cd</code> is equivalent
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to <code class="literal">+cdflag</code>.
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The query options are:
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</p>
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<div class="variablelist"><dl class="variablelist">
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<dt><span class="term"><code class="option">+[no]aaflag</code></span></dt>
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<dd>
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<p>
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A synonym for <em class="parameter"><code>+[no]aaonly</code></em>.
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</p>
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</dd>
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<dt><span class="term"><code class="option">+[no]aaonly</code></span></dt>
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<dd>
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<p>
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Sets the "aa" flag in the query.
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|
</p>
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</dd>
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<dt><span class="term"><code class="option">+[no]additional</code></span></dt>
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<dd>
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<p>
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Display [do not display] the additional section of a
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reply. The default is to display it.
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</p>
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</dd>
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<dt><span class="term"><code class="option">+[no]adflag</code></span></dt>
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<dd>
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<p>
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Set [do not set] the AD (authentic data) bit in the
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query. This requests the server to return whether
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all of the answer and authority sections have all
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been validated as secure according to the security
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|
policy of the server. AD=1 indicates that all records
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have been validated as secure and the answer is not
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from a OPT-OUT range. AD=0 indicate that some part
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of the answer was insecure or not validated. This
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bit is set by default.
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</p>
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</dd>
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|
<dt><span class="term"><code class="option">+[no]all</code></span></dt>
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<dd>
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<p>
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Set or clear all display flags.
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</p>
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</dd>
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|
<dt><span class="term"><code class="option">+[no]answer</code></span></dt>
|
|
<dd>
|
|
<p>
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|
Display [do not display] the answer section of a
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|
reply. The default is to display it.
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</p>
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</dd>
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|
<dt><span class="term"><code class="option">+[no]authority</code></span></dt>
|
|
<dd>
|
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<p>
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|
Display [do not display] the authority section of a
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reply. The default is to display it.
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</p>
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</dd>
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<dt><span class="term"><code class="option">+[no]badcookie</code></span></dt>
|
|
<dd>
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<p>
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Retry lookup with the new server cookie if a
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BADCOOKIE response is received.
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</p>
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</dd>
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<dt><span class="term"><code class="option">+[no]besteffort</code></span></dt>
|
|
<dd>
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<p>
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Attempt to display the contents of messages which are
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malformed. The default is to not display malformed
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answers.
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</p>
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</dd>
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<dt><span class="term"><code class="option">+bufsize=B</code></span></dt>
|
|
<dd>
|
|
<p>
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Set the UDP message buffer size advertised using EDNS0
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to <em class="parameter"><code>B</code></em> bytes. The maximum and
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|
minimum sizes of this buffer are 65535 and 0 respectively.
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|
Values outside this range are rounded up or down
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appropriately. Values other than zero will cause a
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EDNS query to be sent.
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</p>
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</dd>
|
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<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]class</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 class="command"><strong>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]cookie[<span class="optional">=####</span>]</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Send a COOKIE EDNS option, with optional
|
|
value. Replaying a COOKIE from a previous response will
|
|
allow the server to identify a previous client. The
|
|
default is <code class="option">+cookie</code>.
|
|
</p>
|
|
<p>
|
|
<span class="command"><strong>+cookie</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">+[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 class="command"><strong>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">+dscp=value</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Set the DSCP code point to be used when sending the
|
|
query. Valid DSCP code points are in the range
|
|
[0..63]. By default no code point is explicitly set.
|
|
</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]ednsflags[=#]</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Set the must-be-zero EDNS flags bits (Z bits) to the
|
|
specified value. Decimal, hex and octal encodings are
|
|
accepted. Setting a named flag (e.g. DO) will silently be
|
|
ignored. By default, no Z bits are set.
|
|
</p>
|
|
</dd>
|
|
<dt><span class="term"><code class="option">+[no]ednsnegotiation</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Enable / disable EDNS version negotiation. By default
|
|
EDNS version negotiation is enabled.
|
|
</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">code</code> can be
|
|
either an EDNS option name (for example,
|
|
<code class="literal">NSID</code> or <code class="literal">ECS</code>),
|
|
or an arbitrary numeric value. <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]header-only</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Send a query with a DNS header without a question section.
|
|
The default is to add a question section. The query type
|
|
and query name are ignored when this is set.
|
|
</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]idnout</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Convert [do not convert] puny code on output.
|
|
This requires IDN SUPPORT to have been enabled at
|
|
compile time. The default is to convert output.
|
|
</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]mapped</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Allow mapped IPv4 over IPv6 addresses to be used. The
|
|
default is <code class="option">+mapped</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 class="command"><strong>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> if
|
|
<code class="option">+search</code> is set.
|
|
</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 class="command"><strong>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]opcode=value</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Set [restore] the DNS message opcode to the specified
|
|
value. The default value is QUERY (0).
|
|
</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]rdflag</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
A synonym for <em class="parameter"><code>+[no]recurse</code></em>.
|
|
</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 class="command"><strong>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>
|
|
<p>
|
|
'ndots' from <code class="filename">resolv.conf</code> (default 1)
|
|
which may be overridden by <em class="parameter"><code>+ndots</code></em>
|
|
determines if the name will be treated as relative
|
|
or not and hence whether a search is eventually
|
|
performed or not.
|
|
</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. This feature is deprecated.
|
|
Use <span class="command"><strong>delv</strong></span> instead.
|
|
</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-length]</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Send (don't send) an EDNS Client Subnet option with the
|
|
specified IP address or network prefix.
|
|
</p>
|
|
<p>
|
|
<span class="command"><strong>dig +subnet=0.0.0.0/0</strong></span>, or simply
|
|
<span class="command"><strong>dig +subnet=0</strong></span> for short, sends an EDNS
|
|
CLIENT-SUBNET option with an empty address and a source
|
|
prefix-length of zero, which signals a resolver that
|
|
the client's address information must
|
|
<span class="emphasis"><em>not</em></span> be used when resolving
|
|
this query.
|
|
</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 a type
|
|
<code class="literal">any</code> or <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">+timeout=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.
|
|
This feature is deprecated. Use <span class="command"><strong>delv</strong></span> instead.
|
|
</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 class="command"><strong>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>
|
|
If @server is also specified, it affects only the
|
|
initial query for the root zone name servers.
|
|
</p> <p>
|
|
<span class="command"><strong>+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 class="command"><strong>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.
|
|
This feature is deprecated. Use <span class="command"><strong>delv</strong></span> instead.
|
|
</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]unknownformat</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Print all RDATA in unknown RR type presentation format
|
|
(RFC 3597). The default is to print RDATA for known types
|
|
in the type's presentation format.
|
|
</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>
|
|
<dt><span class="term"><code class="option">+[no]zflag</code></span></dt>
|
|
<dd>
|
|
<p>
|
|
Set [do not set] the last unassigned DNS header flag in a
|
|
DNS query. This flag is off by default.
|
|
</p>
|
|
</dd>
|
|
</dl></div>
|
|
<p>
|
|
|
|
</p>
|
|
</div>
|
|
|
|
<div class="refsection">
|
|
<a name="id-1.11"></a><h2>MULTIPLE QUERIES</h2>
|
|
|
|
|
|
<p>
|
|
The BIND 9 implementation of <span class="command"><strong>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 class="command"><strong>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 class="command"><strong>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 class="command"><strong>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="refsection">
|
|
<a name="id-1.12"></a><h2>IDN SUPPORT</h2>
|
|
|
|
<p>
|
|
If <span class="command"><strong>dig</strong></span> has been built with IDN (internationalized
|
|
domain name) support, it can accept and display non-ASCII domain names.
|
|
<span class="command"><strong>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 class="command"><strong>dig</strong></span> runs.
|
|
</p>
|
|
</div>
|
|
|
|
<div class="refsection">
|
|
<a name="id-1.13"></a><h2>FILES</h2>
|
|
|
|
<p><code class="filename">/etc/resolv.conf</code>
|
|
</p>
|
|
<p><code class="filename">${HOME}/.digrc</code>
|
|
</p>
|
|
</div>
|
|
|
|
<div class="refsection">
|
|
<a name="id-1.14"></a><h2>SEE ALSO</h2>
|
|
|
|
<p><span class="citerefentry">
|
|
<span class="refentrytitle">delv</span>(1)
|
|
</span>,
|
|
<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="refsection">
|
|
<a name="id-1.15"></a><h2>BUGS</h2>
|
|
|
|
<p>
|
|
There are probably too many query options.
|
|
</p>
|
|
</div>
|
|
|
|
</div></body>
|
|
</html>
|