Nslookup
A
Unix utility by Andrew Cherenson for querying
Internet domain name servers.
The basic use is to find the
Internet 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 Internet 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.
(ftp://src.doc.ic.ac.uk/computing/operating-systems/unix/bsd-sources/usr.sbin/named/tools/nslookup/).
