HOST(1) BIND9 HOST(1)

NAME
       host - DNS lookup utility

SYNOPSIS
       hhoosstt [-aaCCddllnnrrTTwwvv] [-cc class] [-NN ndots] [-RR number] [-tt type] [-WW wait]
            [-44] [-66] {name} [server]

DESCRIPTION
       hhoosstt 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, hhoosstt prints a short summary of its command line
       arguments and options.

       name 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 hhoosstt will by default perform a reverse lookup for that address.
       server is an optional argument which is either the name or IP address
       of the name server that hhoosstt should query instead of the server or
       servers listed in /etc/resolv.conf.

       The -aa (all) option is equivalent to setting the -vv option and asking
       hhoosstt to make a query of type ANY.

       When the -CC option is used, hhoosstt will attempt to display the SOA
       records for zone name 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.

       The -cc option instructs to make a DNS query of class class. This can be
       used to lookup Hesiod or Chaosnet class resource records. The default
       class is IN (Internet).

       Verbose output is generated by hhoosstt when the -dd or -vv option is used.
       The two options are equivalent. They have been provided for backwards
       compatibility. In previous versions, the -dd option switched on
       debugging traces and -vv enabled verbose output.

       List mode is selected by the -ll option. This makes hhoosstt perform a zone
       transfer for zone name. Transfer the zone printing out the NS, PTR and
       address records (A/AAAA). If combined with -aa all records will be
       printed.

       The -ii option specifies that reverse lookups of IPv6 addresses should
       use the IP6.INT domain as defined in RFC1886. The default is to use
       IP6.ARPA.

       The -NN option sets the number of dots that have to be in name for it to
       be considered absolute. The default value is that defined using the
       ndots statement in /etc/resolv.conf, 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 sseeaarrcchh or ddoommaaiinn
       directive in /etc/resolv.conf.

       The number of UDP retries for a lookup can be changed with the -RR
       option.  number indicates how many times hhoosstt will repeat a query that
       does not get answered. The default number of retries is 1. If number is
       negative or zero, the number of retries will default to 1.

       Non-recursive queries can be made via the -rr option. Setting this
       option clears the RRDD - recursion desired - bit in the query which
       hhoosstt makes. This should mean that the name server receiving the query
       will not attempt to resolve name. The -rr option enables hhoosstt to mimic
       the behavior of a name server by making non-recursive queries and
       expecting to receive answers to those queries that are usually
       referrals to other name servers.

       By default hhoosstt uses UDP when making queries. The -TT 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.

       The -44 option forces hhoosstt to only use IPv4 query transport. The -66
       option forces hhoosstt to only use IPv6 query transport.

       The -tt option is used to select the query type.  type can be any
       recognized query type: CNAME, NS, SOA, SIG, KEY, AXFR, etc. When no
       query type is specified, hhoosstt automatically selects an appropriate
       query type. By default it looks for A, AAAA, and MX records, but if the
       -CC option was given, queries will be made for SOA records, and if name
       is a dotted-decimal IPv4 address or colon-delimited IPv6 address, hhoosstt
       will query for PTR records. 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 (e.g. -t IXFR=12345678).

       The time to wait for a reply can be controlled through the -WW and -ww
       options. The -WW option makes hhoosstt wait for wait seconds. If wait is
       less than one, the wait interval is set to one second. When the -ww
       option is used, hhoosstt will effectively wait forever for a reply. The
       time to wait for a response will be set to the number of seconds given
       by the hardware's maximum value for an integer quantity.

FILES       /etc/resolv.conf

SEE ALSO
       ddiigg(1), nnaammeedd(8).

COPYRIGHT       Copyright (C) 2004, 2005, 2007, 2008 Internet Systems Consortium, Inc.
       ("ISC")
       Copyright (C) 2000-2003 Internet Software Consortium.



BIND9                            Jun 30, 2000                          HOST(1)