I am installinga new Exchange 2007 (172.16.1.9)server with Server 2008 OS. The current Exchange server(172.16.1.1) is 2003 with Server 2003 sp2 OS. It is also a domain controller. The new server is going to be only an exchange server. My issue is that these these two servers are not communicating consistently. I am unable to complete the Exchange installation because of this. From the new server I can ping everything in my network without losing packets except 172.16.1.1. Sometimes packets will send succesfully for 5 mins or so between 1.1 and 1.9, but nothing consistent. It's the same in both directions. Windows firewall is turned off on both servers. Nothing else has these IP addresses on the network. Both servers are located on the same switch, soI have testedusing a different switch. Any ideas of why this would happen would be much appreciated.

on each server look at the arp cache (arp -a) and see ensure each IP in question only has one MAC entry. Then remove everything else from the switch and see if the issue persists with just two devices connected (both servers).I'd also try to update the NIC firmware and drivers, and then possibly try new NICs all together. Mike Crowley: MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator