I had a similar problem when doing support hosting. Static routing wasn't set up on cluster of servers and two ones with almost identical software configuratio

I had a similar problem when doing support hosting. Static routing wasn't set up on cluster of servers and two ones with almost identical software configurations were colliding. It was particularly nasty because once you had logged in to both, you couldn't really identify which machine you were hitting. The solution ended up being to drive to the DC, plug a monitor into the machine, and see Windows' "IP Address Conflict" dialog box on the screen >_<.