I bought a block of static IP's for my own use, using one for the game server.

IP is 70.57.225.85 , although you can use l4d2.irishninja.com, as I bought a domain and set some DNS up it.

If you connect via the "Group Server" window in various games, this will not affect you.

Added a KF custom map server using whitelisted 3rd party maps. Port 7709.
Also added whitelisted mutator to both servers to disable collision during trader time, meaning no trader door blocking.

Left 4 Dead 2 Regular: necronomicon.dnsalias.com:27015
Left 4 Dead 2 Modded: necronomicon.dnsalias.com:27016
Killing Floor (8 player): necronomicon.dnsalias.com:7707 (Default port)