i'm gonna try to do my best to explain it:
i am player A and i'm behind a router A
my mate is player B and is behind router B
the 2 routers are connected to the internet
we are working in the same company and we want to play Red Alert 2 against eachother (we can not use Westwoord server or Strike Team's server )
what do we have to do so we can play against eachother in the same network
( do we have to open Router ports, do we have to download extra tools, ... )
I hope you to find the solution here
