Setup linux as firewall

[gergomiho]

Hello everyone ! I would like to use my linux host as a pre-firewall for a windows server. Since linux has nice filtering I would like to redirect all the data on XX port to a windows based gameserver, but with some filtering. I succeed until the gateway server with pre and postrouting setup, but when the player gets transferred to agentserver some problem occour and the player wont be connected. The gameserver is spoofed his IP address to the linux servers IP address.

I know this is not a specific linux question but I hope anyone already done this.

Thanks in advance

[Lazydog]

What does your network look like?
What do your firewall rules look like?