Steam Client
* UDP 27000 to 27015 inclusive (Game client traffic) * UDP 27015 to 27030 inclusive (Typically Matchmaking and HLTV) * TCP 27014 to 27050 inclusive (Steam downloads)
Dedicated or Listen Servers
* TCP 27015 (SRCDS Rcon port)
In addition to the required ports for Steam, Modern Warfare 2 requires the following ports for multiplayer:
* UDP 1500 (outbound) * UDP 3005 (outbound) * UDP 3101 (outbound) * UDP 28960














Does not work.
Yes it does I use them… ;o