Port forwarding is probably the most commonly used form of NAT. It is commonly used when we have a single public IP address and several resources that must be made accessible to the internet. As a result, instead of assigning a single public IP address to every resource, instead we use one public IP address and assign a separate port to each resource.

Port forwarding is rarely used in corporate networks; in fact, higher-end routers do not have easily configurable ways of setting up port forwarding. Fortunately, however, pfSense is designed to be used on a variety of different networks. Port forwarding is usually a feature found on consumer grade routers, and the inclusion of port forwarding in pfSense is an acknowledgement that pfSense will often be deployed in home and SOHO networks.

Before we get started with port forwarding, we should mention the following: