HOST linux command manual

HOST(1)                                                                HOST(1)

       host - DNS lookup utility

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

       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 dot-
       ted-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  debug-
       ging 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  implementations.  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 expect-
       ing  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 dot-
       ted-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.


       dig(1), named(8).

BIND9                            Jun 30, 2000                         HOST(1)