This recipe will describe how to create a NAT port forwarding entry.

The complexity of Network Address Translation (NAT) rules varies greatly. In this recipe, we will only cover port forwarding rules. There are actually three other types of NAT rules available in pfSense:

• Outbound NAT: As the name implies, this form of NAT applies to outbound traffic and involves replacing local IP addresses and port numbers with the WAN IP and port, so packets can be sent out over the public internet. By default, pfSense is configured to automatically generate outbound NAT rules for local interfaces, but you may have to manually configure outbound NAT rules if you are using a VPN, or in other scenarios in which the automatic rules do not produce the desired result. This form of NAT will be covered in a recipe later in this chapter.

• 1:1 NAT: This form of NAT is typically invoked when you have a set of public IP addresses (for example, for a web or file server) that need to be mapped to a set of private IP addresses (for example, the local addresses of your servers) in a 1:1 manner. This form of NAT will be covered in a recipe later in this chapter.
• NPt: Stands for Network Prefix Translation. This is similar to 1:1 NAT, but for IPv6 addresses instead of IPv4 addresses.