HOST(1) 																   HOST(1)

NAME

       host - DNS lookup utility

SYNOPSIS

       host [ -aCdlnrTwv ]  [ -c class ]  [ -N ndots ]	[ -R number ]  [ -t type ]  [ -W wait ]  name [ server ]

DESCRIPTION

       host  is  a simple utility for performing DNS lookups.  It is normally used to convert names to IP addresses and vice versa.  When no argu-
       ments or options are given, host 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 host 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 host should query instead of the server or servers listed in /etc/resolv.conf.

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

       When the -C option is used, host 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  -c	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 host when the -d or -v option is used. The two options are equivalent. They have been provided for backwards
       compatibility. In previous versions, the -d option switched on debugging traces and -v enabled verbose output.

       List  mode  is selected by the -l option. This makes host perform a zone transfer for zone name. The argument is provided for compatibility
       with older implemementations. This option is equivalent to making a query of type AXFR.

       The -n option specifies that reverse lookups of IPv6 addresses should use the IP6.INT domain and "nibble" labels  as  defined  in  RFC1886.
       The default is to use IP6.ARPA and binary labels as defined in RFC2874.

       The -N 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 search or domain directive in /etc/resolv.conf.

       The  number  of	UDP  retries for a lookup can be changed with the -R option. number indicates how many times host 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 -r option.  Setting this option clears the RD -- recursion desired -- bit in the query which host
       makes.  This should mean that the name server receiving the query will not attempt to resolve name. The -r option enables host to mimic the
       behaviour 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 host uses UDP when making queries. The -T option makes it use a TCP connection when querying the name server. TCP will be auto-
       matically selected for queries that require it, such as zone transfer (AXFR) requests.

       The -t option is used to select the query type.	type can be any recognised query type: CNAME, NS, SOA, SIG, KEY, AXFR, etc. When no  query
       type is specified, host automatically selects an appropriate query type. By default it looks for A records, but if the -C option was given,
       queries will be made for SOA records, and if name is a dotted-decimal IPv4 address or colon-delimited IPv6 address, host will query for PTR
       records.

       The  time  to  wait for a reply can be controlled through the -W and -w options. The -W option makes host wait for wait seconds. If wait is
       less than one, the wait interval is set to one second. When the -w option is used, host 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

       dig(1), named(8).

BIND9								   Jun 30, 2000 							   HOST(1)