If this is not Vista clients, then the following should cover it: ICMP LDAP: TCP 389 SMB: TCP 445 RPC Port Mapper: TCP 135 and then >1024 after the RPC connection is set up. Kerberos (Can't remember if this is UDP or TCP in all cases but Port 88) Darren From: gptalk-bounce@xxxxxxxxxxxxx [mailto:gptalk-bounce@xxxxxxxxxxxxx] On Behalf Of Jonathan Finkbiner Sent: Monday, February 25, 2008 7:48 AM To: gptalk@xxxxxxxxxxxxx Subject: [gptalk] Port Traffic For GPO Quick and easy question: What TCP port(s?) does GPO traffic traverse? I have some software firewalls deployed in the field that I believe are blocking ports needed for proper application of policies. Jonathan Finkbiner <mailto:jfinkbiner@xxxxxxx> Information Services Support Analyst Lifestyle Family Fitness <http://www.lff.com/>