host.docbook revision b5ad6dfea4cc3e7d1d322ac99f1e5a31096837c4
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.0//EN"
297be3708069ef31814d6d75c0d71a50a78feb03Mark Andrews "http://www.oasis-open.org/docbook/xml/4.0/docbookx.dtd"
75c0816e8295e180f4bc7f10db3d0d880383bc1cMark Andrews [<!ENTITY mdash "—">]>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC")
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - Copyright (C) 2000-2002 Internet Software Consortium.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - Permission to use, copy, modify, and distribute this software for any
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - purpose with or without fee is hereby granted, provided that the above
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - copyright notice and this permission notice appear in all copies.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - PERFORMANCE OF THIS SOFTWARE.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein<!-- $Id: host.docbook,v 1.10 2005/07/19 04:55:20 marka Exp $ -->
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <refentryinfo>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </refentryinfo>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <refnamediv>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </refnamediv>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <holder>Internet Systems Consortium, Inc. ("ISC")</holder>
297be3708069ef31814d6d75c0d71a50a78feb03Mark Andrews </copyright>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </copyright>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <refsynopsisdiv>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <arg><option>-c <replaceable class="parameter">class</replaceable></option></arg>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <arg><option>-N <replaceable class="parameter">ndots</replaceable></option></arg>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <arg><option>-R <replaceable class="parameter">number</replaceable></option></arg>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <arg><option>-t <replaceable class="parameter">type</replaceable></option></arg>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <arg><option>-W <replaceable class="parameter">wait</replaceable></option></arg>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <arg><option>-m <replaceable class="parameter">flag</replaceable></option></arg>
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews </cmdsynopsis>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </refsynopsisdiv>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein is a simple utility for performing DNS lookups.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein It is normally used to convert names to IP addresses and vice versa.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein When no arguments or options are given,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein prints a short summary of its command line arguments and options.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <para><parameter>name</parameter> is the domain name that is to be
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater up. It can also be a dotted-decimal IPv4 address or a colon-delimited
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein IPv6 address, in which case <command>host</command> will by
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater perform a reverse lookup for that address.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <parameter>server</parameter> is an optional argument which
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the name or IP address of the name server that <command>host</command>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein should query instead of the server or servers listed in
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater The <option>-a</option> (all) option is equivalent to setting the
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <option>-v</option> option and asking <command>host</command> to make
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein a query of type ANY.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater When the <option>-C</option> option is used, <command>host</command>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater will attempt to display the SOA records for zone
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <parameter>name</parameter> from all the listed
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater authoritative name
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein servers for that zone. The list of name servers is defined by the NS
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater records that are found for the zone.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater The <option>-c</option> option instructs to make a DNS query of class
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <parameter>class</parameter>. This can be used to lookup
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Chaosnet class resource records. The default class is IN (Internet).
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater Verbose output is generated by <command>host</command> when
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <option>-d</option> or <option>-v</option> option is used. The two
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews options are equivalent. They have been provided for backwards
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein compatibility. In previous versions, the <option>-d</option> option
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater switched on debugging traces and <option>-v</option> enabled verbose
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein List mode is selected by the <option>-l</option> option. This makes
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <command>host</command> perform a zone transfer for zone
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <parameter>name</parameter>. Transfer the zone printing out
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein and address records (A/AAAA). If combined with <option>-a</option>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein all records will be printed.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater option specifies that reverse lookups of IPv6 addresses should
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein use the IP6.INT domain as defined in RFC1886.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The default is to use IP6.ARPA.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater The <option>-N</option> option sets the number of dots that have to be
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater in <parameter>name</parameter> for it to be considered
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater default value is that defined using the ndots statement in
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <filename>/etc/resolv.conf</filename>, or 1 if no ndots
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater present. Names with fewer dots are interpreted as relative names and
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater will be searched for in the domains listed in the <type>search</type>
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater The number of UDP retries for a lookup can be changed with the
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <option>-R</option> option. <parameter>number</parameter>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein how many times <command>host</command> will repeat a query
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein not get answered. The default number of retries is 1. If
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <parameter>number</parameter> is negative or zero, the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein retries will default to 1.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein Non-recursive queries can be made via the <option>-r</option> option.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater Setting this option clears the <type>RD</type> — recursion
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein desired — bit in the query which <command>host</command> makes.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater This should mean that the name server receiving the query will not
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein attempt to resolve <parameter>name</parameter>. The
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <option>-r</option> option enables <command>host</command>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the behaviour of a name server by making non-recursive queries and
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater expecting to receive answers to those queries that are usually
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater referrals to other name servers.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein By default <command>host</command> uses UDP when making
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews queries. The
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <option>-T</option> option makes it use a TCP connection when querying
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein the name server. TCP will be automatically selected for queries that
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater require it, such as zone transfer (AXFR) requests.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein The <option>-4</option> option forces <command>host</command> to only
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein use IPv4 query transport. The <option>-6</option> option forces
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <command>host</command> to only use IPv6 query transport.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater The <option>-t</option> option is used to select the query type.
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater <parameter>type</parameter> can be any recognised query
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein NS, SOA, SIG, KEY, AXFR, etc. When no query type is specified,
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <command>host</command> automatically selects an appropriate
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater type. By default it looks for A records, but if the
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews <option>-C</option> option was given, queries will be made for SOA
ab8729140b1ad688ab03e1e9ce438fb1cbb49222Automatic Updater records, and if <parameter>name</parameter> is a
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein dotted-decimal IPv4
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein address or colon-delimited IPv6 address, <command>host</command> will
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein query for PTR records. If a query type of IXFR is chosen the starting
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein serial number can be specified by appending an equal followed by the
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein starting serial number (e.g. -t IXFR=12345678).
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews The time to wait for a reply can be controlled through the
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews <option>-W</option> and <option>-w</option> options. The
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews <option>-W</option> option makes <command>host</command>
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews <parameter>wait</parameter> seconds. If <parameter>wait</parameter>
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews is less than one, the wait interval is set to one second. When the
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews <option>-w</option> option is used, <command>host</command>
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews effectively wait forever for a reply. The time to wait for a response
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews will be set to the number of seconds given by the hardware's maximum
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews value for an integer quantity.
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews The <option>-m</option> can be used to set the memory usage debugging
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews <parameter>record</parameter>, <parameter>usage</parameter> and
71c66a876ecca77923638d3f94cc0783152b2f03Mark Andrews <refentrytitle>dig</refentrytitle><manvolnum>1</manvolnum>
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews </citerefentry>,
5a4557e8de2951a2796676b5ec4b6a90caa5be14Mark Andrews <citerefentry>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein <refentrytitle>named</refentrytitle><manvolnum>8</manvolnum>
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein </citerefentry>.
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - Local variables:
60e5e10f8d2e2b0c41e8abad38cacd867caa6ab2Rob Austein - mode: sgml