host.html revision fb84f9014321c5f33c4682de5661b579fcde318f
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - Copyright (C) 2000, 2001 Internet Software Consortium.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - Permission to use, copy, modify, and distribute this software for any
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - purpose with or without fee is hereby granted, provided that the above
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - copyright notice and this permission notice appear in all copies.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri Pankov - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe - FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri Pankov - NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri Pankov - WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweNAME="GENERATOR"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCONTENT="Modular DocBook HTML Stylesheet Version 1.61
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REFENTRY"
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c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REFNAMEDIV"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>host -- DNS lookup utility</DIV
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REFSYNOPSISDIV"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>Synopsis</H2
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>-aCdlnrTwv</TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REPLACEABLE"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REPLACEABLE"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REPLACEABLE"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REPLACEABLE"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REPLACEABLE"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>] {name} [server]</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REFSECT1"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>DESCRIPTION</H2
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweis a simple utility for performing DNS lookups.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweIt is normally used to convert names to IP addresses and vice versa.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweWhen no arguments or options are given,
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweprints a short summary of its command line arguments and options.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> is the domain name that is to be looked
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweup. It can also be a dotted-decimal IPv4 address or a colon-delimited
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweIPv6 address, in which case <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> will by default
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweperform a reverse lookup for that address.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> is an optional argument which is either
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri Pankovthe name or IP address of the name server that <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweshould query instead of the server or servers listed in
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="FILENAME"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> (all) option is equivalent to setting the
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option and asking <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowea query of type ANY.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>When the <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option is used, <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowewill attempt to display the SOA records for zone
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> from all the listed authoritative name
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweservers for that zone. The list of name servers is defined by the NS
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowerecords that are found for the zone.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option instructs to make a DNS query of class
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>. This can be used to lookup Hesiod or
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweChaosnet class resource records. The default class is IN (Internet).</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>Verbose output is generated by <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option is used. The two
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweoptions are equivalent. They have been provided for backwards
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowecompatibility. In previous versions, the <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweswitched on debugging traces and <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> enabled verbose
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>List mode is selected by the <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option. This makes
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> perform a zone transfer for zone
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>. The argument is provided for
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowecompatibility with older implemementations. This option is equivalent
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweto making a query of type AXFR.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweoption specifies that reverse lookups of IPv6 addresses should
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweuse the IP6.INT domain and "nibble" labels as defined in RFC1886.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweThe default is to use IP6.ARPA and binary labels as defined in RFC2874.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option sets the number of dots that have to be
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> for it to be considered absolute. The
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowedefault value is that defined using the ndots statement in
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="FILENAME"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>, or 1 if no ndots statement is
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowepresent. Names with fewer dots are interpreted as relative names and
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowewill be searched for in the domains listed in the <SPAN
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>search</SPAN
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>domain</SPAN
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> directive in
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="FILENAME"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>The number of UDP retries for a lookup can be changed with the
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option. <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowehow many times <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> will repeat a query that does
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowenot get answered. The default number of retries is 1. If
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> is negative or zero, the number of
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweretries will default to 1.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>Non-recursive queries can be made via the <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweSetting this option clears the <SPAN
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> — recursion
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowedesired — bit in the query which <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweThis should mean that the name server receiving the query will not
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweattempt to resolve <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option enables <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowethe behaviour of a name server by making non-recursive queries and
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweexpecting to receive answers to those queries that are usually
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowereferrals to other name servers.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>By default <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> uses UDP when making queries. The
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option makes it use a TCP connection when querying
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowethe name server. TCP will be automatically selected for queries that
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowerequire it, such as zone transfer (AXFR) requests.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option is used to select the query type.
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> can be any recognised query type: CNAME,
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweNS, SOA, SIG, KEY, AXFR, etc. When no query type is specified,
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> automatically selects an appropriate query
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowetype. By default it looks for A records, but if the
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option was given, queries will be made for SOA
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowerecords, and if <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> is a dotted-decimal IPv4
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweaddress or colon-delimited IPv6 address, <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowequery for PTR records.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe>The time to wait for a reply can be controlled through the
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> options. The
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option makes <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> seconds. If <TT
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="PARAMETER"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweis less than one, the wait interval is set to one second. When the
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="OPTION"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowe> option is used, <B
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="COMMAND"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Loweeffectively wait forever for a reply. The time to wait for a response
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowewill be set to the number of seconds given by the hardware's maximum
c10c16dec587a0662068f6e2991c29ed3a9db943Richard Lowevalue for an integer quantity.</P
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweCLASS="REFSECT1"
c10c16dec587a0662068f6e2991c29ed3a9db943Richard LoweNAME="AEN105"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="FILENAME"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="REFSECT1"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovNAME="AEN109"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri Pankov>SEE ALSO</H2
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="CITEREFENTRY"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="REFENTRYTITLE"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="CITEREFENTRY"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="REFENTRYTITLE"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri Pankov>resolver</SPAN
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="CITEREFENTRY"
a9478106a12424322498e53cf7cd75bd8a4d6004Yuri PankovCLASS="REFENTRYTITLE"