Learn how to fix the pfSense Outbound NAT Not Working error. Our pfSense Support team is here to help you with your questions and concerns.

pfSense Outbound NAT Not Working | Troubleshooting

Dealing with Network Address Translation (NAT) can be a difficult task, especially in anything beyond the most basic networking environments.

Whether you’re managing a home network or a corporate infrastructure, configuring NAT settings often needs attention to detail and troubleshooting ability.

In pfSense software, managing outbound NAT configurations comes with its own set of challenges.

When we use manual outbound NAT in pfSense, particularly in cases involving multiple local subnets or VPN connections, we have to ensure that an outbound NAT entry exists for each subnet.

If we do not, it causes packets to leave the WAN interface with a source address belonging to a private network in fact, this is a telltale sign of a missing outbound NAT rule.

If we opt for automatic outbound NAT, certain conditions must be met.
Firstly, WAN interfaces must have gateways selected. This is done via the Interfaces menu.

Additionally, make sure that LAN interfaces do not have gateways selected.

This ensures that traffic is routed correctly through the WAN interface for NAT processing.

Troubleshooting

Troubleshooting NAT issues often involves going to the pfSense interface and examining the configuration settings.

If the outbound NAT rules table is empty, it means either no interfaces have gateways selected or all interfaces have gateways selected.

In such cases, ensuring that the WAN interface has a default gateway selected can resolve the issue. All we have to do is head to the WAN interface page and choose the default gateway to kickstart the automatic outbound NAT rule creation process.

Additionally, our experts advise reviewing firewall logs for more information. We can check the System logs under Status for information about any errors. This helps with the troubleshooting process.

If the issue still exists, test connectivity using both old and new IP addresses. By configuring a laptop with the existing public IP address and ISP’s next hop router as the gateway, and ensuring connectivity with a public DNS source, we can verify baseline functionality.

Then switch to the new IP addresses and repeat the test to find any configuration issues within the firewall. This also helps identify shortcomings with the ISP’s setup.

With even minor misconfigurations leading to errors, we need to pay attention to detail and troubleshooting carefully. If you are still having trouble, drop us a comment.

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Conclusion

In brief, our Support Experts demonstrated how to troubleshoot the pfSense Outbound NAT Not Working error.