How can I make my internal and external ip address's the same?

I'm trying to do gamespy arcade.

It's called DMZ (De-Militarized Zone). Although not suggested, you can do that if you're behind a router and want to be "in front" of it.

Otherwise, you should find what ports the program is using, and open them instead and redirect them to your inside IP address. That would be a lot safer way of doing it.

MLindahl

Don't use a router.

Let the hackers take your machine instead