Hello,

I've been using this router for some time.

Use Case:

I set up and set up an OpenVPN server with a Raspberry pi. That worked so far. The idea was to use the DDNS service from TP-Link and port forwarding to connect me externally to the local network.

Router Settings: 

I activated the DDNS service from TP-Link in the router and it is also active. I also switched on port forwarding to the Raspberry Pi. As a profile I use the EPlus standard profile, as my provider I have O2.

Port Checking:

When checking whether the port can be reached externally, I noticed that it isn't and neither are all the other ports that I opened for testing, even though they are definitely reachable locally.

Now I noticed the following error:

When I go into the app I have the public address: 10.123.123.250
When I check my public address on the internet: 43.22.123.54
If I resolve the DDNS service to IP address: 43.22.123.54

That means I now have a problem. If I use the public IP address from the app, the ports are reachable. When I resolve to DDNS, I am given a different IP address and it somehow points to me but none of the ports are reachable. For me this means that the DDNS service is totally unnecessary because it gives me the wrong IP address. I don't understand why I even have two IP addresses. In the app and one when I use DDNS or browser to check. Can someone help me with how to turn two into one and then use DDNS?