If you have access to a Unix or Linux shell account, you can use the command "dig
whatever.info" to do a "dig" on a given domain to see what hostnames, IP addresses,
and name servers are associated with it.From Windows, some dig utilities are available,
such as Sam Spade. I think you'll find a number of them at tucows.com.
The
zone file is the master file for a given domain that lists all hosts within it and
their name servers and address records. All domains at all levels have them;
the TLDs have zone files with all the registered domains in them, while second and
higher level domains have zone files listing their hostnames and subdomains.