I've been trying to hunt down a network issue we've been having for a while. We have two Dell T310 servers running Windows Server 2008 R2 on them. Quite a few users have complained that they get dropped off the server (it's a domain controller and a file server, among other things) at random times, and the drops are especially obvious with Access databases. I've also noticed that the ping response time to this server is 3-4ms, and <1 ms to the server that's not having any problems.
I've attempted to troubleshoot the ping issue off-hours, in case it would lead me to the problem that's causing the dropouts. Booting in Safe Mode with Networking cuts the ping down to <1 ms, but anything other than that doesn't seem to work. I've tried disabling all services and startup programs, didn't work. I've swapped switches out and tried isolating the switch from everything else to make sure there's no network storm with no success. I honestly don't know what else to look for.
I also tried to host the Access database on the other server, and had absolutely no problems with network dropouts. However, moving all of the files to that server is not an option, I have to figure out how to fix this one.
Any ideas? Thanks in advance.