nslookup

A Unix utility program, originally by Andrew Cherenson, for querying Internet domain name servers. The basic use is to find the IP address corresponding to a given hostname (or vice versa). By changing the query type (e.g. "set type=CNAME") other types of information can be obtained including CNAME - the canonical name for an alias; HINFO - the host CPU and operating system type; MINFO - mailbox or mail list information; MX - mail exchanger information; NS - the name server for the named zone; PTR - the hostname if the query is an IP address, otherwise the pointer to other information; SOA the domain's start-of-authority information; TXT - text information; UINFO - user information; WKS - supported well-known services. Other types (ANY, AXFR, MB, MD, MF, NULL) are described in RFC 1035.