RFCs - http://www.rfc-editor.org/

internic - Commerce Dept licenses service for domains - href=http://www.internic.net

internic "whois" service - http://www.internic.net/whois.html

Command line "whois" in LINUX.

whois google.com whois 192.42.153.100

Command line "nslookup" in LINUX.

TCP Well known ports - http://www.iana.org/assignments/port-numbers

IP Address assignments http://www.iana.org/ipaddress/ip-addresses.htm