Forwarding Ports with pfSense¶
Forwarding ports on pfSense is a fairly simple process. When adding a port forward, a firewall rule must also be added to allow traffic in to the internal IP address designated by the port forward. There is an option to automatically add this rule when creating a port forward definition, and it is enabled by default.
Port forwarding in current versions has been extended to allow for much more flexible and powerful configurations, but users not accustomed to firewalls allowing advanced NAT capabilities may find it confusing initially.
This section describes each of the fields on the port forward edit screen.
Disabled: Allows the port forward entry to be disabled without removing it from the configuration.
No RDR: Negates redirection for traffic matching what is specified here. For advanced configurations, usually should be unchecked.
Interface: The interface where the traffic is originated, usually WAN
Protocol: The protocol of the traffic to be forwarded.
Source: Allows matching a specific original source of the traffic, and is hidden behind an Advanced button as in most cases it should be “any”, allowing all Internet hosts through. The source port range when using TCP and/or UDP, and will almost always be “any”. The source port is not the same as the destination port, and is normally a random port between 1024-65535.
Destination: Specifies the original destination IP address of the traffic, as seen before being translated, and will usually be WAN address.
Destination Port Range: Specifies the original destination port of the traffic, it is the outside port or ports to forward.
Redirect target IP: The internal IP address where this traffic will be forwarded.
Redirect Target Port: The internal port where this traffic will be forwarded, and is usually the same as the external port as defined in Destination port range. If multiple ports in a range are used for the Destination port range, this is the starting port of the range as it must be the same size range.
Description: A description for reference.
No XMLRPC Sync: Prevents the entry from syncing to other CARP members
NAT reflection: Allows NAT reflection to be enabled or disabled on a per-port forward basis.
Filter rule association: Choose one of Add an associated filter rule gets updated when the port forward is updated, or Add an unassociated filter rule, or pass which passes all traffic that matches the entry without having a firewall rule at all.
To explain how this screen’s functionality translates into English: Take traffic entering the chosen interface, using the specified protocol, initiated from the specified source, destined to the specified destination, and redirect it to the specified target IP and port.
See also: Port Forward Troubleshooting