IP Ports

Overview

In the TCP and UDP protocols used in computer networking, a port is a special number present in the header of a data packet. Ports are typically used to map data to a particular process running on a computer.

Applications implementing common services will normally listen on specific port numbers which have been defined by convention for use with the given protocol.

For a fuller definition see: http://en.wikipedia.org/wiki/IP_port/.

Common ports

Lists of common ports available from the following links:

• http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers/
• http://www.iana.org/assignments/port-numbers/
• http://www.iss.net/security_center/advice/Exploits/Ports/
• http://www.practicallynetworked.com/sharing/app_port_list.htm

Port scanning

A port scanner is a piece of software designed to search a network host for open ports. This is often used by administrators to check the security of their networks and by crackers to compromise it.

For a fuller definition see: http://en.wikipedia.org/wiki/Port_scanning.