Manual Page Result
0
Command: host | Section: 1 | Source: OpenBSD | File: host.1
HOST(1) FreeBSD General Commands Manual HOST(1)
NAME
host - DNS lookup utility
SYNOPSIS
host [-46aCdilrsTVvw] [-c class] [-m flag] [-N ndots] [-R number]
[-t type] [-W wait] name [server]
DESCRIPTION
The host command is a simple utility for performing DNS lookups. It is
normally used to convert names to IP addresses and vice versa.
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 options are as follows:
-4 Use IPv4 only for query transport.
-6 Use IPv6 only for query transport.
-a "All". The -a option is normally equivalent to -v -t ANY. It
also affects the behaviour of the -l list zone option.
-C Check consistency: host will query 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.
-c class
Query class: This can be used to lookup HS (Hesiod) or CH
(Chaosnet) class resource records. The default class is IN
(Internet).
-d Print debugging traces. Equivalent to the -v verbose option.
-i Obsolete. Use the IP6.INT domain for reverse lookups of IPv6
addresses as defined in RFC 1886 and deprecated in RFC 4159. The
default is to use IP6.ARPA as specified in RFC 3596.
-l List zone: The host command performs a zone transfer of zone name
and prints out the NS, PTR and address records (A/AAAA).
Together, the -l -a options print all records in the zone.
-m flag
Memory usage debugging: the flag can be record, usage, or trace.
You can specify the -m option more than once to set multiple
flags.
-N ndots
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 number
Number of retries for UDP queries: If number is negative or zero,
the number of retries will default to 1. The default value is 1.
-r Non-recursive query: Setting this option clears the RD (recursion
desired) bit in the query. This should mean that the name server
receiving the query will not attempt to resolve name. The -r
option enables host to mimic the behavior of a name server by
making non-recursive queries and expecting to receive answers to
those queries that can be referrals to other name servers.
-s Do not send the query to the next name server if any server
responds with a SERVFAIL response, which is the reverse of normal
stub resolver behavior.
-T TCP: 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 automatically selected for queries that
require it, such as zone transfer (AXFR) requests.
-t type
Query type: The type argument can be any recognized query type:
CNAME, NS, SOA, TXT, DNSKEY, AXFR, etc.
When no query type is specified, host automatically selects an
appropriate query type. By default, it looks for A, AAAA, and MX
records. If the -C option is given, queries will be made for SOA
records. If name is a dotted-decimal IPv4 address or colon-
delimited IPv6 address, host 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 (like -t IXFR=12345678).
-V Print the version number and exit.
-v Verbose output. Equivalent to the -d debug option.
-W wait
Timeout: Wait for up to wait seconds for a reply. If wait is
less than one, the wait interval is set to one second.
By default, host will wait for 5 seconds for UDP responses and 10
seconds for TCP connections.
-w Wait forever: The query timeout is set to the maximum possible.
FILES
/etc/resolv.conf
SEE ALSO
dig(1)
AUTHORS
Internet Systems Consortium, Inc.
FreeBSD 14.1-RELEASE-p8 March 31, 2022 FreeBSD 14.1-RELEASE-p8