Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
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 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	refer-
       rals 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	recog-
       nised 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.


       dig(1), named(8).

BIND9				 Jun 30, 2000			       HOST(1)


Want to link to this manual page? Use this URL:

home | help