Questions:
Are you using DDNS? What does DC3 say it's IP address is there?
I doubt DDNS is being used. DC3 has a private static IP address
What is differnet about DC3 compared to DC1&2 and why do you think it is an issue?
Good question. The server was setup in a hurried manner and not configured correctly, from what I'm told. All this was done by an out sourced company. I know it is an issue because the other 2 DCs are not gerenating these errors Ottawa and Toronto.
Does DC3 have the loopback apapter or RRAS or ISA, etc setup?
I wish I could answer this question. The server is in Calgary. No ISA, no RRAS as far as I tell. The only other hardware is an Exchange server and some SonicWall products.