Need some serious help!!

Ok, first of all I used to be able to run a GMOD Dedicated server and my steam client would still be able to get to servers before, and now I can’t run both at the same time because when i run the server the steam client cannot connect to any servers what so ever on any game when the server is running. (ALL PORTS ARE FORWARDED) and computer is pretty decent. I know it’s not my connection and I know it’s not my computer because I’ve upgraded a few pieces on it since the last time about 6-8 months ago I had both my Client/Steam and the server running on simultaneously and everything worked fine. 5-6 re-formats later and and 2 or 3 re-installs it isn’t working this time around.

Server On = Steam not able to connect to any multiplayer servers over any game.

Server Off = Good Connection, and connection to any server.

Fresh Dedicated Server Download, Don’t need updates, so I know all that I have put in this post (is NOT the problem) and I am at a loss for ideas I just would like to have it running to where i had it so long ago :frowning:

Any help would be awesome, and I will give gratitude to all those who are helpful.