http://forum.1cpublishing.eu/showthr...ion+Steam+lost
http://forum.1cpublishing.eu/showthr...ost#post343607
If you are behind a router, you can host only in Lobby room. Maybe you can take care of all the ports mentioned in the Steam FAQ but not sure CloD also needs many ports forwarded. Maybe you need a good network specialist to set up gateway, DNS, etc. as mentioned in one of the links.