Hosting Issue's / Router

Hi, i recently got my hands on a set of Server files for Massively Multiplayer online game. My Internet Connection is 1.5m ADSL which is behind a router to host this server i had to Forward all the needed ports.
I have succesfully done this and the server runs A+ i can have other people connect to it, but seeing i am behind the router for myself to connect i must edit the client to connect to my "internal ip"

Now if i connect to the server first just as i put it up, i can get ingame no problems at all, but people outside using My External Ip in the client can not connect.
This is Vise versa if somone using an External Ip connects to my server first

Any Help on how i would b able to have myself and othr people both playing w/o using another pc would be greatly appreciated

 

When you use a Router and open ports. The open port is associated with a specific Computer's IP and become like the Routing agent.

If you connect first using your Internal IP the Router cannot use it any more and vice versa. If your Server allow communication via few ports change the ports that your internal computer is using with the server. When you use a Router and open ports. The open port is associated with the Computer's IP and become like the Routing agent.

If you connect first using your Internal IP the Router cannot use it any more and vice versa. I am not familiar with Game Servers, but might be that the DMZ is the cure.