I have a new WIN2K3 server setup as a domain controller in an existing network (mixed protocol IPX - TCP/IP) this is my first Windows server in this network. I installed McAfee, configured DNS, Active Directory, and DHCP. I configured the NIC with a static IP address 192.168.0.5 and the gateway as 192.168.0.2 (my firewall) and ran all of the patches and updates from the Internet. I set the DC to use a .local domain. I can access other windows boxes on the network, and I can ping network devices from the server, but I cannot join the domain, or ping the server from an XP workstation. If I boot the server in safe mode, I can then ping from a workstation, I could also join the domain while the server was in safe mode, but I cannot login to the DC. I could however browse to a shared volume wihout logging in. I ran DCDIAG and found no errors. I reviewed the event logs and nothing looks wrong. I understand that the default security settings are stringent and suspect that incoming IP or UDP traffic is being blocked. Where do I look from here?