I believe the created socket at 0.0.0.0 in port 0 is referring to the socket in which the server is listening for a connection at any address and possibly port 0 would be any port specified from that incoming IP address. I could be wrong on this.
If you’re using the default online subsystem to connect it shouldn’t take much to establish a connection outside of just OpenLevel-> ipaddress:port you won’t even need to specify the port if you are only running one server instance at that address.
If you want to run multiple server instances on the same machine, just swap out the port in the BaseEngine.ini to your choosing and package the server and then swap out the maps, go back into the BaseEngine.ini change to port to another port and package again. Rinse and repeat.
Example:
Game #1 x.x.x.x:7777
Game #2 x.x.x.x:7778
Game #3 x.x.x.x:7779
Assuming you are using a remote windows server in the end game, I know for a fact that you will need to enable/allow connections specifically at those port ranges in the server instance itself as it won’t allow any outside connections out of the box on a new server instance without making those changes in the firewall’s security settings.