Mac OS X Tiger in a Nutshell

Name

dig

Synopsis

dig [@server] host [querytype] [queryclass] [options]

Queries Internet domain name servers. Like the nslookup command, dig displays information about host as returned by the default or a specified nameserver. With dig, you specify all aspects of the query on the command line; there’s no interactive mode as with nslookup.

Specify the nameserver to query with @ server, using either a domain name or an IP in server. The default is to query the nameservers in resolv.conf. Specify the type of query in querytype; the default is to look up address records. The supported types are:

A

Host’s Internet address.

ANY

Any available information (default).

AXFR

Request zone transfer.

HINFO

Host CPU and operating system type.

MX

Mail exchanger.

NS

Nameserver for the named zone.

SOA

Domain start-of-authority.

Use queryclass to specify query class of either IN (Internet) or ANY. Default is IN.

Options

The following descriptions cover dig’s basic operation; for a complete description, refer to dig’s manpage.

-x address

Reverse map address, which allows you to locate a hostname when only an IP number is available. Implies ANY as the query type.

-p port

Send queries to the specified port instead of port 53, the default.

+norec[urse]

Turn off recursion (on by default).

+trace

Iteratively trace queries from the root servers. Show the results of each subquery as it resolves from the root servers to the final destination.

+vc

Send TCP-based queries (queries are UDP by default).