host(1)

Use only the IPv4 query transport.

Use only the IPv6 query transport.

Equivalent to using -v -t ANY.

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.

Make a DNS query of class class. This can be used to look up class resource records. The values for class are:

The class values are case-insensitive.

Generate verbose output. Now equivalent to the -v option. -d is provided for backwards compatibility. In previous versions, it switched on debugging traces.

Use the IP6.INT domain, as defined in RFC 1886, to perform reverse lookups of IPv6 addresses. The default is to use IP6.ARPA.

Select list mode. host performs a zone transfer for zone name. Transfer the zone, printing out the NS, PTR and address records (A/AAAA). If -l is combined with -a, all records will be printed.

Set the number of dots that have to be in name for it to be considered absolute. The default value is defined using the ndots statement in /etc/resolv.conf, or is 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.

Set the number of UDP retries for a lookup. 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 is set to 1.

Make nonrecursive queries. 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 the name operand.

This option enables host to mimic the behavior of a name server by making nonrecursive queries and expecting to receive answers to those queries that are usually referrals to other name servers.

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.

Select the query type. type can be any recognized query type: A, AAAA, ANY, AXFR, CNAME, IXFR, KEY, NS, PTR, SIG, SOA, and so on. For potential values, see the set querytype command in nslookup(1) and the Zone File discussion in named.conf(4).

The type values are case-insensitive.

When the -t option is omitted, host automatically selects an appropriate query type. By default, it looks for A records, but if the -C option is given, queries are made for SOA records. If the name operand is an IPv4 or IPv6 address, host queries for PTR records.

For a query type of IXFR, you can specify the starting serial number by appending an equals sign followed by the starting serial number (for example, -t IXFR=12345678).

Generate verbose output.

Set the time to wait for a reply to wait seconds. If wait is less than 1, the wait interval is set to 1.

Effectively wait forever for a reply. The time to wait for a response is set to the number of seconds given by the hardware's maximum value for an integer quantity.

The domain name that is to be looked up. It can also be an IPv4 or IPv6 address, in which case host will, by default, perform a reverse lookup for that address.

The name or IP address of the name server that host should query. The default is the server or servers listed in /etc/resolv.conf.