Port Forward Troubleshooting

If you are having problems with a port forward, try the following.

1. If you did not exactly follow the How can I forward ports with pfSense? guide, delete anything you have tried, and start from scratch with those instructions.

2. Port forwards do not work internally unless you enable reflection. Always test port forwards from outside your network.

3. If you're still having problems, edit the firewall rule that passes traffic for the NAT entry, and enable logging. Save and Apply Changes. Then try to access it again from the outside. Check your firewall logs to see if the traffic shows as being permitted or denied.

4. Use tcpdump to see what's happening on the wire. This is the best means of finding the problem, but requires the most networking expertise. Start with the WAN interface, and use a filter for the appropriate protocol and port. Attempt to access from outside your network and see if it shows up. If not, your ISP may be blocking the traffic, or for Virtual IPs, you may have an incorrect configuration. If you do see the traffic on the WAN interface, switch to the inside interface and perform a similar capture. If the traffic is not leaving the inside interface, you have a NAT or firewall rule configuration problem. If it is leaving the interface, and no traffic is coming back from the destination machine, its default gateway may be missing or incorrect, or it may not be listening on that port. For certain types of traffic you may see return traffic indicating the host is not listening on that port. For TCP, this would be a TCP RST. For UDP, it may be an ICMP Unreachable message.

Common Problems

1. NAT and firewall rules not correctly added (see How can I forward ports with pfSense?). Hint: You probably do NOT want to set a source port.

2. Firewall enabled on client machine.

3. Client machine is not using pfSense as its default gateway.

4. Client machine not actually listening on the port being forwarded.

5. ISP or something upstream of pfSense is blocking the port being forwarded

6. Trying to test from inside your network, need to test from an outside machine.

7. Incorrect or missing Virtual IP configuration for additional public IP addresses.

8. The pfSense router is not the border router. If there is something else between pfSense and your ISP, you must also replicate port forwards and associated rules there.

9. Forwarding ports to a server behind a Captive Portal. You must add an IP bypass both to and from the server's IP in order for a port forward to work behind a Captive Portal.