Has anyone out there had issues using Identity NAT and Windows Server 2008? We have a client that recently upgraded their Windows 2k3 server to 2008, and started getting "Duplicate IP" messages on their 2008 boxes. Through some testing we were also able to reproducethe issue with Windows 7, but not XP.
We got rid of the the ID NAT, and added the communication to our NAT exemption ACL and the problem went away.
This has happened at 2 different client sites, but neither gave us enough time to really dig into why this was happening.
I suspect it has something to do with GARP and how the new MS platforms interpret it, but that's really a guess. I'm not very strong on the MS side.