man.host.html revision 5f0c46ca5f68c2148c735aa52d7541baac249c34
d6fa26d0adaec6c910115be34fe7a5a5f402c14fMark Andrews<!--
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - Copyright (C) 2000-2015 Internet Systems Consortium, Inc. ("ISC")
32098293b78922a5fbd10906afa28624820d3756Tinderbox User -
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - This Source Code Form is subject to the terms of the Mozilla Public
5347c0fcb04eaea19d9f39795646239f487c6207Tinderbox User - License, v. 2.0. If a copy of the MPL was not distributed with this
5347c0fcb04eaea19d9f39795646239f487c6207Tinderbox User - file, You can obtain one at http://mozilla.org/MPL/2.0/.
5347c0fcb04eaea19d9f39795646239f487c6207Tinderbox User-->
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<html>
d6fa26d0adaec6c910115be34fe7a5a5f402c14fMark Andrews<head>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<title>host</title>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<link rel="home" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual">
14a656f94b1fd0ababd84a772228dfa52276ba15Evan Hunt<link rel="up" href="Bv9ARM.ch13.html" title="Manual pages">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<link rel="prev" href="man.dig.html" title="dig">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<link rel="next" href="man.delv.html" title="delv">
cd32f419a8a5432fbb139f56ee73cbf68b9350ccTinderbox User</head>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<div class="navheader">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<table width="100%" summary="Navigation header">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<tr><th colspan="3" align="center">host</th></tr>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<tr>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<td width="20%" align="left">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<a accesskey="p" href="man.dig.html">Prev</a>�</td>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<th width="60%" align="center">Manual pages</th>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<td width="20%" align="right">�<a accesskey="n" href="man.delv.html">Next</a>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein</td>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein</tr>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein</table>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<hr>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein</div>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<div class="refentry">
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<a name="man.host"></a><div class="titlepage"></div>
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<div class="refnamediv">
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<h2>Name</h2>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p>host &#8212; DNS lookup utility</p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein</div>
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<div class="refsynopsisdiv">
af40ebed6257e4ac1996144530b3de317cf4da11Tinderbox User<h2>Synopsis</h2>
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<div class="cmdsynopsis"><p><code class="command">host</code> [<code class="option">-aCdlnrsTwv</code>] [<code class="option">-c <em class="replaceable"><code>class</code></em></code>] [<code class="option">-N <em class="replaceable"><code>ndots</code></em></code>] [<code class="option">-R <em class="replaceable"><code>number</code></em></code>] [<code class="option">-t <em class="replaceable"><code>type</code></em></code>] [<code class="option">-W <em class="replaceable"><code>wait</code></em></code>] [<code class="option">-m <em class="replaceable"><code>flag</code></em></code>] [<code class="option">-4</code>] [<code class="option">-6</code>] [<code class="option">-v</code>] [<code class="option">-V</code>] {name} [server]</p></div>
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User</div>
af40ebed6257e4ac1996144530b3de317cf4da11Tinderbox User<div class="refsection">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<a name="id-1.14.3.7"></a><h2>DESCRIPTION</h2>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><span class="command"><strong>host</strong></span>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User is a simple utility for performing DNS lookups.
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User It is normally used to convert names to IP addresses and vice versa.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein When no arguments or options are given,
af40ebed6257e4ac1996144530b3de317cf4da11Tinderbox User <span class="command"><strong>host</strong></span>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User prints a short summary of its command line arguments and options.
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User </p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p><em class="parameter"><code>name</code></em> is the domain name that is to be
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User looked
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User up. It can also be a dotted-decimal IPv4 address or a colon-delimited
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User IPv6 address, in which case <span class="command"><strong>host</strong></span> will by
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein default
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein perform a reverse lookup for that address.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <em class="parameter"><code>server</code></em> is an optional argument which
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein is either
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the name or IP address of the name server that <span class="command"><strong>host</strong></span>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein should query instead of the server or servers listed in
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User <code class="filename">/etc/resolv.conf</code>.
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User </p>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User</div>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User<div class="refsection">
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<a name="id-1.14.3.8"></a><h2>OPTIONS</h2>
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User<div class="variablelist"><dl class="variablelist">
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User<dt><span class="term">-4</span></dt>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User<dd><p>
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews Use IPv4 only for query transport.
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews See also the <code class="option">-6</code> option.
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews </p></dd>
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews<dt><span class="term">-6</span></dt>
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews<dd><p>
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews Use IPv6 only for query transport.
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews See also the <code class="option">-4</code> option.
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews </p></dd>
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews<dt><span class="term">-a</span></dt>
48abcd3eb789fdd24a2e0a6155b25e6979a39ae0Mark Andrews<dd><p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein "All". The <code class="option">-a</code> option is normally equivalent
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User to <code class="option">-v -t <code class="literal">ANY</code></code>.
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User It also affects the behaviour of the <code class="option">-l</code>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein list zone option.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </p></dd>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-c <em class="replaceable"><code>class</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dd><p>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User Query class: This can be used to lookup HS (Hesiod) or CH
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User (Chaosnet) class resource records. The default class is IN
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein (Internet).
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </p></dd>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-C</span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dd><p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Check consistency: <span class="command"><strong>host</strong></span> will query the
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User SOA records for zone <em class="parameter"><code>name</code></em> from all
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User the listed authoritative name servers for that zone. The
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User list of name servers is defined by the NS records that are
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein found for the zone.
af40ebed6257e4ac1996144530b3de317cf4da11Tinderbox User </p></dd>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User<dt><span class="term">-d</span></dt>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User<dd><p>
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews Print debugging traces.
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews Equivalent to the <code class="option">-v</code> verbose option.
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews </p></dd>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-i</span></dt>
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews<dd><p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Obsolete.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Use the IP6.INT domain for reverse lookups of IPv6
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews addresses as defined in RFC1886 and deprecated in RFC4159.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The default is to use IP6.ARPA as specified in RFC3596.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </p></dd>
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews<dt><span class="term">-l</span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dd>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User<p>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User List zone:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The <span class="command"><strong>host</strong></span> command performs a zone transfer of
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User zone <em class="parameter"><code>name</code></em> and prints out the NS,
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews PTR and address records (A/AAAA).
fd2597f75693a2279fdf588bd40dfe2407c42028Tinderbox User </p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Together, the <code class="option">-l -a</code>
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User options print all records in the zone.
7911e6f9de303bca5a3d8b34f4330c8f7cecffaeTinderbox User </p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein</dd>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dt><span class="term">-N <em class="replaceable"><code>ndots</code></em></span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dd><p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The number of dots that have to be
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein in <em class="parameter"><code>name</code></em> for it to be considered
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein absolute. The default value is that defined using the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein ndots statement in <code class="filename">/etc/resolv.conf</code>,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein or 1 if no ndots statement is present. Names with fewer
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein dots are interpreted as relative names and will be
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein searched for in the domains listed in
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the <span class="type">search</span> or <span class="type">domain</span> directive
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews in <code class="filename">/etc/resolv.conf</code>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </p></dd>
cd32f419a8a5432fbb139f56ee73cbf68b9350ccTinderbox User<dt><span class="term">-r</span></dt>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<dd><p>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Non-recursive query:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Setting this option clears the RD (recursion desired) bit
350e5eecadfc5ee72b11b2cc46828c9a0bcd717cTinderbox User in the query. This should mean that the name server
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein receiving the query will not attempt to
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein resolve <em class="parameter"><code>name</code></em>.
The <code class="option">-r</code> option
enables <span class="command"><strong>host</strong></span> to mimic the behavior of a
name server by making non-recursive queries and expecting
to receive answers to those queries that can be
referrals to other name servers.
</p></dd>
<dt><span class="term">-R <em class="replaceable"><code>number</code></em></span></dt>
<dd><p>
Number of retries for UDP queries:
If <em class="parameter"><code>number</code></em> is negative or zero, the
number of retries will default to 1. The default value is
1, or the value of the <em class="parameter"><code>attempts</code></em>
option in <code class="filename">/etc/resolv.conf</code>, if set.
</p></dd>
<dt><span class="term">-s</span></dt>
<dd><p>
Do <span class="emphasis"><em>not</em></span> send the query to the next
nameserver if any server responds with a SERVFAIL
response, which is the reverse of normal stub resolver
behavior.
</p></dd>
<dt><span class="term">-t <em class="replaceable"><code>type</code></em></span></dt>
<dd>
<p>
Query type:
The <em class="parameter"><code>type</code></em> argument can be any
recognized query type: CNAME, NS, SOA, TXT, DNSKEY, AXFR, etc.
</p>
<p>
When no query type is specified, <span class="command"><strong>host</strong></span>
automatically selects an appropriate query type. By default, it
looks for A, AAAA, and MX records.
If the <code class="option">-C</code> option is given, queries will
be made for SOA records.
If <em class="parameter"><code>name</code></em> is a dotted-decimal IPv4
address or colon-delimited IPv6
address, <span class="command"><strong>host</strong></span> will query for PTR
records.
</p>
<p>
If a query type of IXFR is chosen the starting serial
number can be specified by appending an equal followed by
the starting serial number
(like <code class="option">-t <code class="literal">IXFR=12345678</code></code>).
</p>
</dd>
<dt><span class="term">-T</span></dt>
<dd><p>
TCP:
By default, <span class="command"><strong>host</strong></span> uses UDP when making
queries. The <code class="option">-T</code> option makes it use a TCP
connection when querying the name server. TCP will be
automatically selected for queries that require it, such
as zone transfer (AXFR) requests.
</p></dd>
<dt><span class="term">-m <em class="replaceable"><code>flag</code></em></span></dt>
<dd><p>
Memory usage debugging: the flag can
be <em class="parameter"><code>record</code></em>, <em class="parameter"><code>usage</code></em>,
or <em class="parameter"><code>trace</code></em>. You can specify
the <code class="option">-m</code> option more than once to set
multiple flags.
</p></dd>
<dt><span class="term">-v</span></dt>
<dd><p>
Verbose output.
Equivalent to the <code class="option">-d</code> debug option.
Verbose output can also be enabled by setting
the <em class="parameter"><code>debug</code></em> option
in <code class="filename">/etc/resolv.conf</code>.
</p></dd>
<dt><span class="term">-V</span></dt>
<dd><p>
Print the version number and exit.
</p></dd>
<dt><span class="term">-w</span></dt>
<dd><p>
Wait forever: The query timeout is set to the maximum possible.
See also the <code class="option">-W</code> option.
</p></dd>
<dt><span class="term">-W <em class="replaceable"><code>wait</code></em></span></dt>
<dd>
<p>
Timeout: Wait for up to <em class="parameter"><code>wait</code></em>
seconds for a reply. If <em class="parameter"><code>wait</code></em> is
less than one, the wait interval is set to one second.
</p>
<p>
By default, <span class="command"><strong>host</strong></span> will wait for 5
seconds for UDP responses and 10 seconds for TCP
connections. These defaults can be overridden by
the <em class="parameter"><code>timeout</code></em> option
in <code class="filename">/etc/resolv.conf</code>.
</p>
<p>
See also the <code class="option">-w</code> option.
</p>
</dd>
</dl></div>
</div>
<div class="refsection">
<a name="id-1.14.3.9"></a><h2>IDN SUPPORT</h2>
<p>
If <span class="command"><strong>host</strong></span> has been built with IDN (internationalized
domain name) support, it can accept and display non-ASCII domain names.
<span class="command"><strong>host</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>host</strong></span> runs.
</p>
</div>
<div class="refsection">
<a name="id-1.14.3.10"></a><h2>FILES</h2>
<p><code class="filename">/etc/resolv.conf</code>
</p>
</div>
<div class="refsection">
<a name="id-1.14.3.11"></a><h2>SEE ALSO</h2>
<p><span class="citerefentry"><span class="refentrytitle">dig</span>(1)</span>,
<span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>.
</p>
</div>
</div>
<div class="navfooter">
<hr>
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left">
<a accesskey="p" href="man.dig.html">Prev</a>�</td>
<td width="20%" align="center"><a accesskey="u" href="Bv9ARM.ch13.html">Up</a></td>
<td width="40%" align="right">�<a accesskey="n" href="man.delv.html">Next</a>
</td>
</tr>
<tr>
<td width="40%" align="left" valign="top">dig�</td>
<td width="20%" align="center"><a accesskey="h" href="Bv9ARM.html">Home</a></td>
<td width="40%" align="right" valign="top">�delv</td>
</tr>
</table>
</div>
<p xmlns:db="http://docbook.org/ns/docbook" style="text-align: center;">BIND 9.11.0b3</p>
</body>
</html>