So I got here a little concern about my port-forwarding plan...I want to deploy a new port forwarding protocol on my router to start a particular game server. Now here's the problem, my router's WAN is connected to another router, in a case that the router that it is connected to is locked, I don't know the username and password, the internet connection is not mine and I just tap mine into them. Can I still be able to use my router's port forwarding?
I heard things about NAT and I don't know much about it, and I want to know if that could help. And also a friend suggests me to use a VPN for my game server to externally connect with my peers, but I only want to use port forwarding and I'm comfortable using it... Any help guys????