Port forwarding

Port forwarding, also referred to as port mapping, is a method of forwarding a network port from one network node to another. This technique can allow an external user to reach a port on a private IP address (inside a LAN) from the outside using a NAT-enabled router.

Port forwarding allows remote computers (e.g. public machines on the Internet) to connect to a specific computer within a private LAN.

For example:
 forwarding of port 80 to run an HTTP webserver within private LAN from internet
 forwarding of port 22 to allow Secure Shell access within private LAN from internet
 forwarding of port 21 to allow FTP access within private LAN from internet

Port forwarding is not necessary with IPv6, because every IPv6-enabled device has a public IPv6 address.

Related pages
 Internet protocol suite
 Communications protocol

 References 

Category:Internet protocols