If you tried to implement DDNS but it is not working, there are several potential causes. If you are using DDNS via a DDNS provider, you should confirm that you set up the domain correctly and also confirm that your provider's service works with pfSense. Once you have done that, you should go through the client configuration step by step. Many DDNS providers have instructions for different routers, including pfSense routers, and if such instructions are available, you should follow them. Also, make sure you have installed and configured your provider's updater software correctly. If you have gone through all of these steps and DDNS is still not working, you may want to contact your provider's technical support, if such support is available.

If you are trying to implement RFC 2136 DDNS, the process involves setting up the initial records on the DNS server, generating the keys, and configuring the client under pfSense. You need to make sure both the server and client configuration were done correctly. Some possible sources of problems include:

• The TTL setting is too long, which could result in cached nameservers not updating quickly enough
• Not setting the client up to update IPv6 (AAAA) records in an environment where IPv6 is being used–check the Record Type setting
• Trying to update a zone record without checking the Use TCP instead of UDP checkbox

Another point that seems fairly obvious but is worth mentioning is that you need to check DDNS functionality from the other side of the firewall. This is especially true if you have services that rely on NAT port-forwarding. In most cases, NAT is configured to forward traffic to certain ports only if they come in on one of the WAN interfaces. Since internal traffic does not come in on a WAN interface, NAT will not be invoked, and no port-forwarding will take place.