Mac OS X 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 name server. With dig, you specify all aspects of the query on the command line; there’s no interactive mode as with nslookup.

Specifies the name server to query with @ server, using either a domain name or an IP in server. The default is to query the name servers in resolv.conf. Specifies 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, allowing 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).

+vc

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