That would make sense. I'm assuming the router associates this random port with the internal IP address of the computer that sent the request.

Yes, that's standard router procedures.

(LAN IP / internet IP)
192.168.1.2:61455 <-> 3.43.125.18:12233.

You'll need port forwarding to host a game on a specific router port.

That would make sense. I'm assuming the router associates this random port with the internal IP address of the computer that sent the request.

Yes, that's standard router procedures.

(LAN IP / internet IP)
192.168.1.2:61455 <-> 3.43.125.18:12233.

You'll need port forwarding to host a game on a specific internet port.