Cannot join my own gameserver via my external IP

In short, when I launch a game server on Windows, I can only join it via the local IP address but not via my public IP. The server and the client are on the same machine, same interface. The server is run directly on the host, no Virtual Box. Here is my setup: I have a router that forwards a 3457 UDP port to 192.168.0.102 . 192.168.0.102 is the local IP of my host computer. I launch a gameserver on this 192.168.0.102 interface and these commands show the following: netstat -ano | findstr 3457 UDP 192.168.0.102:3457 *:* 34192 Let's assume 50.100.30.68 is my public IP. ncat -vnzu 50.100.30.68 34

Question by t7e on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.