Originally posted by MatrixCPA
Your problem may or may not have a simple solution. Are your friends using you ip address to connect? Or is the problem that it doesn't show up in the server list? Are you behind a firewall/router? If so, have you forwarded all the ncessary ports? Are you running the dedicated server binary or the mp game to host the server? If the former, what's your command line and config look like? If the later, are you setting it up as dedicated in the setup screen?
So there is no straight answer? Lame, I'll just join empty servers and have my friends join...
At least on counterstrike it was easy. Just create the server with in game instructions, and it's done. I'm not gonna bother and do all this work just for a server.