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a32ddb6cabb635ca29ccff87f8bf5c6af3b78ecfstoddard - Copyright (C) 2004-2015 Internet Systems Consortium, Inc. ("ISC")
2a6c49cfaef5979a5a06098f3ce987cd76769409manoj - Copyright (C) 2000-2003 Internet Software Consortium.
2a6c49cfaef5979a5a06098f3ce987cd76769409manoj - Permission to use, copy, modify, and/or distribute this software for any
9a93784d34c322d1996e8a7b794a75230eac81a4wrowe - purpose with or without fee is hereby granted, provided that the above
9a93784d34c322d1996e8a7b794a75230eac81a4wrowe - copyright notice and this permission notice appear in all copies.
a096f8d13bee05fd6ea8b9b50b6c2e818eace7d1striker - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
dba571e5c5a2586c7e2b382789f3250136ff7577jwoolley - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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bf3d1782a29630335a1df535eb395355ab1cd154jwoolley - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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d8028365066fca602bf35d014530a1802114378crbb - PERFORMANCE OF THIS SOFTWARE.
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af4c982a7cf4515f124935f99a329744035fc699slive<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>
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe is a simple utility for performing DNS lookups.
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe It is normally used to convert names to IP addresses and vice versa.
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe When no arguments or options are given,
4b62424416882687387923b3130b96241503cbe0jerenkrantz prints a short summary of its command line arguments and options.
5ca8e11fadb6f7a8d9d0367c1800205c99d4bcd6jerenkrantz<p><em class="parameter"><code>name</code></em> is the domain name that is to be
dbec4658981e4f9127e8676457c28d42932be7cdtrawick up. It can also be a dotted-decimal IPv4 address or a colon-delimited
1b7e9aeb9867a1c94e24e8ae491d2dfcd0d225e3jerenkrantz IPv6 address, in which case <span><strong class="command">host</strong></span> will by
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz perform a reverse lookup for that address.
f95a0b59eb24c631f15bd83e20c6cf823c432d83trawick <em class="parameter"><code>server</code></em> is an optional argument which
f95a0b59eb24c631f15bd83e20c6cf823c432d83trawick the name or IP address of the name server that <span><strong class="command">host</strong></span>
f95a0b59eb24c631f15bd83e20c6cf823c432d83trawick should query instead of the server or servers listed in
418f39e60a288f855ec033b566744489c3bbbf39trawick The <code class="option">-a</code> (all) option is equivalent to setting the
cc22a72861c58dda7f3768613aec864e4c4e0353striker <code class="option">-v</code> option and asking <span><strong class="command">host</strong></span> to make
f95a0b59eb24c631f15bd83e20c6cf823c432d83trawick a query of type ANY.
ae72c92fd41562d7c0e8627c093fcbbae4ac9ef2coar When the <code class="option">-C</code> option is used, <span><strong class="command">host</strong></span>
ddafc111b94558ef4e2d7357ceda623315566ce3slive will attempt to display the SOA records for zone
93f189f1198f539d3cfa75a15b23dcde60ee35ffrbb <em class="parameter"><code>name</code></em> from all the listed
93f189f1198f539d3cfa75a15b23dcde60ee35ffrbb authoritative name
b3b4e853e4958357ee2d50e2fe41effecfde9eedwrowe servers for that zone. The list of name servers is defined by the NS
a4d9e6fdcd5d2ddd93a896b42a1d607ed258c316ianh records that are found for the zone.
93f189f1198f539d3cfa75a15b23dcde60ee35ffrbb The <code class="option">-c</code> option instructs to make a DNS query of class
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz <em class="parameter"><code>class</code></em>. This can be used to lookup
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz Chaosnet class resource records. The default class is IN (Internet).
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz Verbose output is generated by <span><strong class="command">host</strong></span> when
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz <code class="option">-d</code> or <code class="option">-v</code> option is used. The two
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz options are equivalent. They have been provided for backwards
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz compatibility. In previous versions, the <code class="option">-d</code> option
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe switched on debugging traces and <code class="option">-v</code> enabled verbose
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz output. Verbose output can also be enabled by setting the
f4cb04eb78da02a38fcdd87489dc7b660107d55fjerenkrantz <em class="parameter"><code>debug</code></em> option in
1af5c0e25a649bb298e25ddfa5418fa18bdcb107aaron List mode is selected by the <code class="option">-l</code> option. This makes
82455c2e3b6991846fbcbf0c9e41f57dbc681217brianp <span><strong class="command">host</strong></span> perform a zone transfer for zone
82455c2e3b6991846fbcbf0c9e41f57dbc681217brianp <em class="parameter"><code>name</code></em>. Transfer the zone printing out
1b3f48fd6b1ccb8745f908e40156c5a85ca3c347jerenkrantz and address records (A/AAAA). If combined with <code class="option">-a</code>
b05930e6008f69bd323abe0c10f81f40ffd27983brianp all records will be printed.
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe option specifies that reverse lookups of IPv6 addresses should
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe use the IP6.INT domain as defined in RFC1886.
b3b4e853e4958357ee2d50e2fe41effecfde9eedwrowe The default is to use IP6.ARPA.
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe The <code class="option">-N</code> option sets the number of dots that have to be
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe in <em class="parameter"><code>name</code></em> for it to be considered
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe absolute. The
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe default value is that defined using the ndots statement in
6362fd5c48f6b2193f5d356a9747172101b24e91jerenkrantz <code class="filename">/etc/resolv.conf</code>, or 1 if no ndots
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe statement is
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe present. Names with fewer dots are interpreted as relative names and
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe will be searched for in the domains listed in the <span class="type">search</span>
630f5fc1277582643fe0f831a4830e15127bd047jwoolley The number of UDP retries for a lookup can be changed with the
630f5fc1277582643fe0f831a4830e15127bd047jwoolley <code class="option">-R</code> option. <em class="parameter"><code>number</code></em>
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe how many times <span><strong class="command">host</strong></span> will repeat a query
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe not get answered. If
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe <em class="parameter"><code>number</code></em> is negative or zero, the
56b2562cb4041a21bc313fde3204beabdb758800jwoolley retries will default to 1. The default value is 1, or
56b2562cb4041a21bc313fde3204beabdb758800jwoolley the value of the <em class="parameter"><code>attempts</code></em> option in
56b2562cb4041a21bc313fde3204beabdb758800jwoolley <code class="filename">/etc/resolv.conf</code>, if set.
56b2562cb4041a21bc313fde3204beabdb758800jwoolley Non-recursive queries can be made via the <code class="option">-r</code> option.
f881b8be216de36c6b964324c772450bca38a4e6trawick Setting this option clears the <span class="type">RD</span> — recursion
f881b8be216de36c6b964324c772450bca38a4e6trawick desired — bit in the query which <span><strong class="command">host</strong></span> makes.
f881b8be216de36c6b964324c772450bca38a4e6trawick This should mean that the name server receiving the query will not
f881b8be216de36c6b964324c772450bca38a4e6trawick attempt to resolve <em class="parameter"><code>name</code></em>. The
f881b8be216de36c6b964324c772450bca38a4e6trawick <code class="option">-r</code> option enables <span><strong class="command">host</strong></span>
56b2562cb4041a21bc313fde3204beabdb758800jwoolley the behavior of a name server by making non-recursive queries and
b05930e6008f69bd323abe0c10f81f40ffd27983brianp expecting to receive answers to those queries that are usually
b05930e6008f69bd323abe0c10f81f40ffd27983brianp referrals to other name servers.
b05930e6008f69bd323abe0c10f81f40ffd27983brianp By default, <span><strong class="command">host</strong></span> uses UDP when making
4c7dab038d90d7feb67ef8ddbfacc77be8c9dbf0jwoolley queries. The
4c7dab038d90d7feb67ef8ddbfacc77be8c9dbf0jwoolley <code class="option">-T</code> option makes it use a TCP connection when querying
4c7dab038d90d7feb67ef8ddbfacc77be8c9dbf0jwoolley the name server. TCP will be automatically selected for queries that
4c7dab038d90d7feb67ef8ddbfacc77be8c9dbf0jwoolley require it, such as zone transfer (AXFR) requests.
8c8fbb8546af54582539898be704411a60058d85trawick The <code class="option">-4</code> option forces <span><strong class="command">host</strong></span> to only
8c8fbb8546af54582539898be704411a60058d85trawick use IPv4 query transport. The <code class="option">-6</code> option forces
f9b8e29cfca92cf0a996e8ab17fa1a1f447cecc7stoddard <span><strong class="command">host</strong></span> to only use IPv6 query transport.
a23b1c5a74208b03884c09a6f9dd5d6c97fa6415trawick The <code class="option">-t</code> option is used to select the query type.
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe <em class="parameter"><code>type</code></em> can be any recognized query
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe type: CNAME,
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe NS, SOA, SIG, KEY, AXFR, etc. When no query type is specified,
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe <span><strong class="command">host</strong></span> automatically selects an appropriate
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe type. By default, it looks for A, AAAA, and MX records, but if the
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe <code class="option">-C</code> option was given, queries will be made for SOA
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe records, and if <em class="parameter"><code>name</code></em> is a
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe dotted-decimal IPv4
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe address or colon-delimited IPv6 address, <span><strong class="command">host</strong></span> will
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe query for PTR records. If a query type of IXFR is chosen the starting
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe serial number can be specified by appending an equal followed by the
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe starting serial number (e.g. -t IXFR=12345678).
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe The time to wait for a reply can be controlled through the
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe <code class="option">-W</code> and <code class="option">-w</code> options. The
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe <code class="option">-W</code> option makes <span><strong class="command">host</strong></span>
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe <em class="parameter"><code>wait</code></em> seconds. If <em class="parameter"><code>wait</code></em>
2fb49a1d25f38421a68d31b4cbb5d9293fdeafbewrowe is less than one, the wait interval is set to one second. When the
f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe <code class="option">-w</code> option is used, <span><strong class="command">host</strong></span>
638a9edaf48cf003cd40ac25ee8c25f572107414stoddard effectively wait forever for a reply. The time to wait for a response
638a9edaf48cf003cd40ac25ee8c25f572107414stoddard will be set to the number of seconds given by the hardware's maximum
638a9edaf48cf003cd40ac25ee8c25f572107414stoddard value for an integer quantity. By default, <span><strong class="command">host</strong></span>
db2d668e6233d8949b35ee7f9f42f444758f9ce9rbb will wait for 5 seconds for UDP responses and 10 seconds for TCP
db2d668e6233d8949b35ee7f9f42f444758f9ce9rbb connections. These defaults can be overridden by the
db2d668e6233d8949b35ee7f9f42f444758f9ce9rbb <em class="parameter"><code>timeout</code></em> option in
db2d668e6233d8949b35ee7f9f42f444758f9ce9rbb The <code class="option">-s</code> option tells <span><strong class="command">host</strong></span>
1ea5221b240a8b41a07c6fb04aab5a73adcddabfaaron <span class="emphasis"><em>not</em></span> to send the query to the next nameserver
1ea5221b240a8b41a07c6fb04aab5a73adcddabfaaron if any server responds with a SERVFAIL response, which is the
1ea5221b240a8b41a07c6fb04aab5a73adcddabfaaron reverse of normal stub resolver behavior.
1ea5221b240a8b41a07c6fb04aab5a73adcddabfaaron The <code class="option">-m</code> can be used to set the memory usage debugging
5d12baef135b5d3cb94745e007a1575398469724jerenkrantz <em class="parameter"><code>record</code></em>, <em class="parameter"><code>usage</code></em> and
5d12baef135b5d3cb94745e007a1575398469724jerenkrantz The <code class="option">-V</code> option causes <span><strong class="command">host</strong></span>
5d12baef135b5d3cb94745e007a1575398469724jerenkrantz to print the version number and exit.
b865daaa4ef731a7066ee6d97e2aae36c7743939jerenkrantz If <span><strong class="command">host</strong></span> has been built with IDN (internationalized
f881b8be216de36c6b964324c772450bca38a4e6trawick domain name) support, it can accept and display non-ASCII domain names.
f881b8be216de36c6b964324c772450bca38a4e6trawick <span><strong class="command">host</strong></span> appropriately converts character encoding of
f881b8be216de36c6b964324c772450bca38a4e6trawick domain name before sending a request to DNS server or displaying a
dc098c7ce5d36179c504d09fc722d190683d0262aaron reply from the server.
dc098c7ce5d36179c504d09fc722d190683d0262aaron If you'd like to turn off the IDN support for some reason, defines
dc098c7ce5d36179c504d09fc722d190683d0262aaron the <code class="envar">IDN_DISABLE</code> environment variable.
dc098c7ce5d36179c504d09fc722d190683d0262aaron The IDN support is disabled if the variable is set when
dc098c7ce5d36179c504d09fc722d190683d0262aaron <span><strong class="command">host</strong></span> runs.
33f5961d34a8b5390cebad0543b3ebe67830e5d7jerenkrantz<p><span class="citerefentry"><span class="refentrytitle">dig</span>(1)</span>,
33f5961d34a8b5390cebad0543b3ebe67830e5d7jerenkrantz <span class="citerefentry"><span class="refentrytitle">named</span>(8)</span>.
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f610c7c704235bc327dbe9b62982f5b3f8e30a77wrowe<p style="text-align: center;">BIND 9.11.0pre-alpha</p>