host(1M)						  System Administration Commands						  host(1M)

NAME

       host - DNS lookup utility

SYNOPSIS

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

DESCRIPTION

       The host utility performs simple DNS lookups. It is normally used to convert names to IP addresses and IP addresses to names. When no argu-
       ments or options are given, host prints a short summary of its command line arguments and options.

       The name argument 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 by default performs a reverse lookup for that address. The optional server argument 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.

OPTIONS

       The following options are supported:

       -a	       Equivalent to setting the -v option and asking host to make a query of type ANY.

       -c class        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).

       -C	       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.

       -d	       Generate verbose output. This option is equivalent to -v. These two options are provided  for  backward	compatibility.	In
		       previous versions, the -d option switched on debugging traces and -v enabled verbose output.

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

       -n	       Specify 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.

       -N ndots        Set  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.

       -r	       Make  a	non-recursive query. Setting this option clears the RD (recursion desired) bit in the query made by host. The name
		       server receiving the query does 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.

       -R number       Change the number of UDP retries for a lookup. The number argument 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.

       -t type	       Select the query type. The type argument can be any recognised query type: CNAME, NS, SOA, SIG, KEY, and AXFR,  among  oth-
		       ers.  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 is specified, queries are made for SOA records. If name is a dotted-decimal IPv4  address	or
		       colon-delimited IPv6 address, host queries for PTR records.

       -T	       Use a TCP connection when querying the name server. TCP is automatically selected for queries that require it, such as zone
		       transfer (AXFR) requests. By default host uses UDP when making queries.

       -v	       Generate verbose output. This option is equivalent to -d.

       -w	       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 max-
		       imum value for an integer quantity.

       -W wait	       Wait for wait seconds for a reply.  If wait is less than one, the wait interval is set to one second.

FILES

       /etc/resolv.conf        Resolver configuration file

ATTRIBUTES

       See for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       |Availability		     |SUNWbind9 		   |
       |Interface Stability	     |External			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       dig(1M), named(1M), attributes(5)

NOTES

       Source for BIND9 is available in the SUNWbind9S package.

SunOS 5.10							    15 Dec 2004 							  host(1M)