Port numbers, TCP/UDP, & IP Address

Port numbers are integers in the range 1-65535 used to distinguish between different services offered by a given machine on the internet.

Each internet machine has one space of 65535 port numbers for TCP connections and a second, separate space of 65535 port numbers for UDP connections.

These port numbers form the only way of distinguishing between different processes or users on the same machine using the UDP and TCP Internet protocols: An internet IP address (128.95.44.22, say) plus a port number form the most specific Internet address these protocols understand.

 

Reference:

http://muq.org/~cynbe/muq/mufref_564.html

[tool] Best Free Online Whois

“WHOIS (pronounced as the phrase who is) is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block, or an autonomous system, but is also used for a wider range of other information. The protocol stores and delivers database content in a human-readable format.^[1] The WHOIS protocol is documented in RFC 3912.”

http://who.is/

http://who.is/whois-ip/ip-address/<IP Address>

http://who.is/whois-ip/ip-address/8.8.8.8

http://who.is/whois/<Domain Name>

http://who.is/whois/example.com/

http://www.domaintools.com/

http://whois.domaintools.com/<IP Address>

http://whois.domaintools.com/8.8.8.8

http://whois.domaintools.com/<Domain Name>

http://whois.domaintools.com/example.com

http://www.t1shopper.com/tools/

http://www.all-nettools.com/toolbox/smart-whois.php

http://www.samdns.com/default.aspx

REFERENCE

http://en.wikipedia.org/wiki/Whois