Firewall on Windows2000 Server

[Rootz]

People often ask me about some firewall software to protect their servers (Windows2000).
I usually set up routers with IP filters... I mean REAL hardware firewalls, I avoid using firewall software on server systems (at this time those customer people complain I want to spill the most money from them).

I tested some zone alarm pro (brr), sygate... commercial stuff on windows2000 server... apart from not being certified applications for that system, they often screw up services (worse on domain controllers).
I was wondering... anyone knows a firewall software certified to run on W2k Server? and anybody of you had that running with no hassle?

 

[spikemic]

isa (internet security and acceleration) server 2000, Microsoft's firewall/proxy server......
run it on mine, works nicely, had no problems

have it with exchange 2000, and web services and dns all running on an ad domain controller........