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16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - Copyright (C) 2004-2006 Internet Systems Consortium, Inc. ("ISC")
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - Copyright (C) 2000-2003 Internet Software Consortium.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - Permission to use, copy, modify, and distribute this software for any
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - purpose with or without fee is hereby granted, provided that the above
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - copyright notice and this permission notice appear in all copies.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync<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>] {name} [server]</p></div>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync<p><span><strong class="command">host</strong></span>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync is a simple utility for performing DNS lookups.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync It is normally used to convert names to IP addresses and vice versa.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync When no arguments or options are given,
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync prints a short summary of its command line arguments and options.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync<p><em class="parameter"><code>name</code></em> is the domain name that is to be
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync up. It can also be a dotted-decimal IPv4 address or a colon-delimited
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync IPv6 address, in which case <span><strong class="command">host</strong></span> will by
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync perform a reverse lookup for that address.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <em class="parameter"><code>server</code></em> is an optional argument which
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync the name or IP address of the name server that <span><strong class="command">host</strong></span>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync should query instead of the server or servers listed in
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The <code class="option">-a</code> (all) option is equivalent to setting the
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-v</code> option and asking <span><strong class="command">host</strong></span> to make
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync a query of type ANY.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync When the <code class="option">-C</code> option is used, <span><strong class="command">host</strong></span>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync will attempt to display the SOA records for zone
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <em class="parameter"><code>name</code></em> from all the listed
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync authoritative name
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync servers for that zone. The list of name servers is defined by the NS
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync records that are found for the zone.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The <code class="option">-c</code> option instructs to make a DNS query of class
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <em class="parameter"><code>class</code></em>. This can be used to lookup
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync Chaosnet class resource records. The default class is IN (Internet).
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync Verbose output is generated by <span><strong class="command">host</strong></span> when
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-d</code> or <code class="option">-v</code> option is used. The two
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync options are equivalent. They have been provided for backwards
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync compatibility. In previous versions, the <code class="option">-d</code> option
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync switched on debugging traces and <code class="option">-v</code> enabled verbose
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync List mode is selected by the <code class="option">-l</code> option. This makes
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <span><strong class="command">host</strong></span> perform a zone transfer for zone
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <em class="parameter"><code>name</code></em>. Transfer the zone printing out
6a6893202d87603d08774af6eb11e1d7001f6c92vboxsync the NS, PTR
6a6893202d87603d08774af6eb11e1d7001f6c92vboxsync and address records (A/AAAA). If combined with <code class="option">-a</code>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync all records will be printed.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync option specifies that reverse lookups of IPv6 addresses should
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync use the IP6.INT domain as defined in RFC1886.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The default is to use IP6.ARPA.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The <code class="option">-N</code> option sets the number of dots that have to be
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync in <em class="parameter"><code>name</code></em> for it to be considered
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync absolute. The
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync default value is that defined using the ndots statement in
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="filename">/etc/resolv.conf</code>, or 1 if no ndots
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync statement is
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync present. Names with fewer dots are interpreted as relative names and
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync will be searched for in the domains listed in the <span class="type">search</span>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The number of UDP retries for a lookup can be changed with the
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-R</code> option. <em class="parameter"><code>number</code></em>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync how many times <span><strong class="command">host</strong></span> will repeat a query
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync not get answered. The default number of retries is 1. If
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <em class="parameter"><code>number</code></em> is negative or zero, the
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync retries will default to 1.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync Non-recursive queries can be made via the <code class="option">-r</code> option.
6a6893202d87603d08774af6eb11e1d7001f6c92vboxsync Setting this option clears the <span class="type">RD</span> — recursion
6a6893202d87603d08774af6eb11e1d7001f6c92vboxsync desired — bit in the query which <span><strong class="command">host</strong></span> makes.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync This should mean that the name server receiving the query will not
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync attempt to resolve <em class="parameter"><code>name</code></em>. The
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-r</code> option enables <span><strong class="command">host</strong></span>
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync the behaviour of a name server by making non-recursive queries and
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync expecting to receive answers to those queries that are usually
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync referrals to other name servers.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync By default <span><strong class="command">host</strong></span> uses UDP when making
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync queries. The
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-T</code> option makes it use a TCP connection when querying
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync the name server. TCP will be automatically selected for queries that
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync require it, such as zone transfer (AXFR) requests.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The <code class="option">-4</code> option forces <span><strong class="command">host</strong></span> to only
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync use IPv4 query transport. The <code class="option">-6</code> option forces
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <span><strong class="command">host</strong></span> to only use IPv6 query transport.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The <code class="option">-t</code> option is used to select the query type.
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <em class="parameter"><code>type</code></em> can be any recognised query
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync type: CNAME,
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync NS, SOA, SIG, KEY, AXFR, etc. When no query type is specified,
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <span><strong class="command">host</strong></span> automatically selects an appropriate
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync type. By default it looks for A records, but if the
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-C</code> option was given, queries will be made for SOA
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync records, and if <em class="parameter"><code>name</code></em> is a
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync dotted-decimal IPv4
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync address or colon-delimited IPv6 address, <span><strong class="command">host</strong></span> will
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync query for PTR records. If a query type of IXFR is chosen the starting
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync serial number can be specified by appending an equal followed by the
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync starting serial number (e.g. -t IXFR=12345678).
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync The time to wait for a reply can be controlled through the
16a8d09569a2ebd598cef72fa605be6fb4563607vboxsync <code class="option">-W</code> and <code class="option">-w</code> options. The