4.21. host - DNS lookup utility¶
host [-a] [-C] [-d] [-l] [-n] [-r] [-s] [-T] [-w] [-v] [-c <class>] [-N <num-dots>] [-R <number>] [-t <type>] [-W <num-seconds>] [-m <flag>] [[-4] | [-6]] [-v] [-V] <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 arguments 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 nameserver that host should query instead
of the server or servers listed in
This program may be removed from the Loop distribution in the future. Please use dig(1) instead.
Set the query class. The default class is IN (Internet). Other usable classes are HS (Hesiod) or CH (Chaosnet).
Check consistency. host will query the SOA records for zone <name> from all the listed authoritative nameservers for that zone. The list of nameservers is defined by the NS records that are found for the zone.
TODOMUKS: Remove this option.
List zone. The host command performs a zone transfer of zone <name> and prints out the NS, PTR and address records (A/AAAA).
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
Non-recursive query. Setting this option clears the RD DNS message header flag in the query. This should mean that the nameserver receiving the query will not attempt to resolve <name>. The
-roption enables host to mimic the behavior of a nameserver by making non-recursive queries and expecting to receive answers to those queries that can be referrals to other nameservers.
Number of retries for UDP queries. If <count> is less than 1, it will be set to 1. The default value is 1.
Do not send the query to the next nameserver if any server responds with a SERVFAIL response, which is the reverse of normal stub resolver behavior.
Specifies the record type. The <type> argument can be any recognized RR 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
-Coption 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).
Use TCP. By default, host uses UDP when making queries. The
-Toption makes it use a TCP connection when querying the nameserver. TCP will be automatically selected for queries that require it, such as zone transfer (AXFR) requests.
Print the program's version and exit.
4.21.5. See also¶
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