I am trying to set up multiplayer for a 2d platforming party game. So far it works great over LAN connection, but when I tried to play with my friends across the internet, nobody was able to join the server. When I discovered the problem, I thought that connecting to my public external ip address, instead of my local ip address would fix the issue, but neither me nor my friends can connect to the server in that situation. I'm looking for information about what to do next but I'm not having much luck. Does anyone know what is going wrong?