mirror of
https://github.com/isc-projects/bind9.git
synced 2026-02-21 00:40:39 -05:00
405 lines
12 KiB
Text
405 lines
12 KiB
Text
<!DOCTYPE book [
|
|
<!ENTITY mdash "—">]>
|
|
<!--
|
|
- Copyright (C) Internet Systems Consortium, Inc. ("ISC")
|
|
-
|
|
- This Source Code Form is subject to the terms of the Mozilla Public
|
|
- License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
- file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
-
|
|
- See the COPYRIGHT file distributed with this work for additional
|
|
- information regarding copyright ownership.
|
|
-->
|
|
|
|
<!-- Converted by db4-upgrade version 1.0 -->
|
|
<refentry xmlns:db="http://docbook.org/ns/docbook" version="5.0" xml:id="man.host">
|
|
<info>
|
|
<date>2009-01-20</date>
|
|
</info>
|
|
<refentryinfo>
|
|
<corpname>ISC</corpname>
|
|
<corpauthor>Internet Systems Consortium, Inc.</corpauthor>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>host</refentrytitle>
|
|
<manvolnum>1</manvolnum>
|
|
<refmiscinfo>BIND9</refmiscinfo>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>host</refname>
|
|
<refpurpose>DNS lookup utility</refpurpose>
|
|
</refnamediv>
|
|
|
|
<docinfo>
|
|
<copyright>
|
|
<year>2000</year>
|
|
<year>2001</year>
|
|
<year>2002</year>
|
|
<year>2004</year>
|
|
<year>2005</year>
|
|
<year>2007</year>
|
|
<year>2008</year>
|
|
<year>2009</year>
|
|
<year>2014</year>
|
|
<year>2015</year>
|
|
<year>2016</year>
|
|
<year>2017</year>
|
|
<year>2018</year>
|
|
<year>2019</year>
|
|
<holder>Internet Systems Consortium, Inc. ("ISC")</holder>
|
|
</copyright>
|
|
</docinfo>
|
|
|
|
<refsynopsisdiv>
|
|
<cmdsynopsis sepchar=" ">
|
|
<command>host</command>
|
|
<arg choice="opt" rep="norepeat"><option>-aACdlnrsTUwv</option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-c <replaceable class="parameter">class</replaceable></option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-N <replaceable class="parameter">ndots</replaceable></option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-R <replaceable class="parameter">number</replaceable></option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-t <replaceable class="parameter">type</replaceable></option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-W <replaceable class="parameter">wait</replaceable></option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-m <replaceable class="parameter">flag</replaceable></option></arg>
|
|
<group choice="opt" rep="norepeat">
|
|
<arg choice="opt" rep="norepeat"><option>-4</option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-6</option></arg>
|
|
</group>
|
|
<arg choice="opt" rep="norepeat"><option>-v</option></arg>
|
|
<arg choice="opt" rep="norepeat"><option>-V</option></arg>
|
|
<arg choice="req" rep="norepeat">name</arg>
|
|
<arg choice="opt" rep="norepeat">server</arg>
|
|
</cmdsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsection><info><title>DESCRIPTION</title></info>
|
|
|
|
|
|
<para><command>host</command>
|
|
is a simple utility for performing DNS lookups.
|
|
It is normally used to convert names to IP addresses and vice versa.
|
|
When no arguments or options are given,
|
|
<command>host</command>
|
|
prints a short summary of its command line arguments and options.
|
|
</para>
|
|
|
|
<para><parameter>name</parameter> is the domain name that is to be
|
|
looked
|
|
up. It can also be a dotted-decimal IPv4 address or a colon-delimited
|
|
IPv6 address, in which case <command>host</command> will by
|
|
default
|
|
perform a reverse lookup for that address.
|
|
<parameter>server</parameter> is an optional argument which
|
|
is either
|
|
the name or IP address of the name server that <command>host</command>
|
|
should query instead of the server or servers listed in
|
|
<filename>/etc/resolv.conf</filename>.
|
|
</para>
|
|
|
|
</refsection>
|
|
|
|
<refsection><info><title>OPTIONS</title></info>
|
|
|
|
<variablelist>
|
|
|
|
<varlistentry>
|
|
<term>-4</term>
|
|
<listitem>
|
|
<para>
|
|
Use IPv4 only for query transport.
|
|
See also the <option>-6</option> option.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-6</term>
|
|
<listitem>
|
|
<para>
|
|
Use IPv6 only for query transport.
|
|
See also the <option>-4</option> option.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-a</term>
|
|
<listitem>
|
|
<para>
|
|
"All". The <option>-a</option> option is normally equivalent
|
|
to <option>-v -t <literal>ANY</literal></option>.
|
|
It also affects the behaviour of the <option>-l</option>
|
|
list zone option.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-A</term>
|
|
<listitem>
|
|
<para>
|
|
"Almost all". The <option>-A</option> option is equivalent
|
|
to <option>-a</option> except RRSIG, NSEC, and NSEC3
|
|
records are omitted from the output.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-c <replaceable class="parameter">class</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Query class: This can be used to lookup HS (Hesiod) or CH
|
|
(Chaosnet) class resource records. The default class is IN
|
|
(Internet).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-C</term>
|
|
<listitem>
|
|
<para>
|
|
Check consistency: <command>host</command> will query the
|
|
SOA records for zone <parameter>name</parameter> from all
|
|
the listed authoritative name servers for that zone. The
|
|
list of name servers is defined by the NS records that are
|
|
found for the zone.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-d</term>
|
|
<listitem>
|
|
<para>
|
|
Print debugging traces.
|
|
Equivalent to the <option>-v</option> verbose option.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-l</term>
|
|
<listitem>
|
|
<para>
|
|
List zone:
|
|
The <command>host</command> command performs a zone transfer of
|
|
zone <parameter>name</parameter> and prints out the NS,
|
|
PTR and address records (A/AAAA).
|
|
</para>
|
|
<para>
|
|
Together, the <option>-l -a</option>
|
|
options print all records in the zone.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-N <replaceable class="parameter">ndots</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
The number of dots that have to be
|
|
in <parameter>name</parameter> for it to be considered
|
|
absolute. The default value is that defined using the
|
|
ndots statement in <filename>/etc/resolv.conf</filename>,
|
|
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 <type>search</type> or <type>domain</type> directive
|
|
in <filename>/etc/resolv.conf</filename>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-r</term>
|
|
<listitem>
|
|
<para>
|
|
Non-recursive query:
|
|
Setting this option clears the RD (recursion desired) bit
|
|
in the query. This should mean that the name server
|
|
receiving the query will not attempt to
|
|
resolve <parameter>name</parameter>.
|
|
The <option>-r</option> option
|
|
enables <command>host</command> 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.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-R <replaceable class="parameter">number</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Number of retries for UDP queries:
|
|
If <parameter>number</parameter> is negative or zero, the
|
|
number of retries will default to 1. The default value is
|
|
1, or the value of the <parameter>attempts</parameter>
|
|
option in <filename>/etc/resolv.conf</filename>, if set.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-s</term>
|
|
<listitem>
|
|
<para>
|
|
Do <emphasis>not</emphasis> send the query to the next
|
|
nameserver if any server responds with a SERVFAIL
|
|
response, which is the reverse of normal stub resolver
|
|
behavior.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-t <replaceable class="parameter">type</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Query type:
|
|
The <parameter>type</parameter> argument can be any
|
|
recognized query type: CNAME, NS, SOA, TXT, DNSKEY, AXFR, etc.
|
|
</para>
|
|
<para>
|
|
When no query type is specified, <command>host</command>
|
|
automatically selects an appropriate query type. By default, it
|
|
looks for A, AAAA, and MX records.
|
|
If the <option>-C</option> option is given, queries will
|
|
be made for SOA records.
|
|
If <parameter>name</parameter> is a dotted-decimal IPv4
|
|
address or colon-delimited IPv6
|
|
address, <command>host</command> will query for PTR
|
|
records.
|
|
</para>
|
|
<para>
|
|
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 <option>-t <literal>IXFR=12345678</literal></option>).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-T</term>
|
|
<term>-U</term>
|
|
<listitem>
|
|
<para>
|
|
TCP/UDP:
|
|
By default, <command>host</command> uses UDP when making
|
|
queries. The <option>-T</option> 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. Type ANY queries default
|
|
to TCP but can be forced to UDP initially using <option>-U</option>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-m <replaceable class="parameter">flag</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Memory usage debugging: the flag can
|
|
be <parameter>record</parameter>, <parameter>usage</parameter>,
|
|
or <parameter>trace</parameter>. You can specify
|
|
the <option>-m</option> option more than once to set
|
|
multiple flags.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-v</term>
|
|
<listitem>
|
|
<para>
|
|
Verbose output.
|
|
Equivalent to the <option>-d</option> debug option.
|
|
Verbose output can also be enabled by setting
|
|
the <parameter>debug</parameter> option
|
|
in <filename>/etc/resolv.conf</filename>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-V</term>
|
|
<listitem>
|
|
<para>
|
|
Print the version number and exit.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-w</term>
|
|
<listitem>
|
|
<para>
|
|
Wait forever: The query timeout is set to the maximum possible.
|
|
See also the <option>-W</option> option.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>-W <replaceable class="parameter">wait</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
Timeout: Wait for up to <parameter>wait</parameter>
|
|
seconds for a reply. If <parameter>wait</parameter> is
|
|
less than one, the wait interval is set to one second.
|
|
</para>
|
|
<para>
|
|
By default, <command>host</command> will wait for 5
|
|
seconds for UDP responses and 10 seconds for TCP
|
|
connections. These defaults can be overridden by
|
|
the <parameter>timeout</parameter> option
|
|
in <filename>/etc/resolv.conf</filename>.
|
|
</para>
|
|
<para>
|
|
See also the <option>-w</option> option.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
</variablelist>
|
|
|
|
</refsection>
|
|
|
|
<refsection><info><title>IDN SUPPORT</title></info>
|
|
|
|
<para>
|
|
If <command>host</command> has been built with IDN (internationalized
|
|
domain name) support, it can accept and display non-ASCII domain names.
|
|
<command>host</command> 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, define
|
|
the <envar>IDN_DISABLE</envar> environment variable.
|
|
The IDN support is disabled if the variable is set when
|
|
<command>host</command> runs.
|
|
</para>
|
|
</refsection>
|
|
|
|
<refsection><info><title>FILES</title></info>
|
|
|
|
<para><filename>/etc/resolv.conf</filename>
|
|
</para>
|
|
</refsection>
|
|
|
|
<refsection><info><title>SEE ALSO</title></info>
|
|
|
|
<para><citerefentry>
|
|
<refentrytitle>dig</refentrytitle><manvolnum>1</manvolnum>
|
|
</citerefentry>,
|
|
<citerefentry>
|
|
<refentrytitle>named</refentrytitle><manvolnum>8</manvolnum>
|
|
</citerefentry>.
|
|
</para>
|
|
</refsection>
|
|
|
|
</refentry>
|