...

• Usage statistics for individual IP addresses
  • Offers both an interactive form, or via a shortcut to get the usage statistics for the computer currently being used.
• IP/MAC address tracking tools

DNS/

...

CNAME/AREC tool

• http://dnsdb.cit.cornell.edu/dnsdb-cgi/list_domain.pl

Selection from CIT's FAQ

• What is an A record and why do I need one?
• What is a CNAME?

And CIT's domain name glossary.

See also

• Cornell's email forwarding service