Network Address Translation

Network Address Translation (NAT) refers to the process of modifying network address information contained in datagram packet headers while they are in transit, generally across a pfSense® device or similar system, in order to map an address on one subnet to an address on another.

In practice the most common use of NAT is to allow a private LAN to communicate with the public Internet (outbound NAT) and to allow access to servers on the private LAN from the Internet (port forwards).

The NAT settings in pfSense software are accessed via the Firewall > NAT menu in the webGUI.

Configuration of NAT in pfSense software is categorized into four areas: Port Forwards, 1:1 (One to One) NAT, Outbound NAT, and NPt (Network Prefix Translation) for IPv6