I have a network problem that I just can't seem to resolve. I am consulting for a client that has a network that consists of two servers and aprox 20 workstations. Server 1 is running Windows 2003 server standard, and is the Domain Controller. Server 2 is Windows 2003 64 bit and is running Exchange 2007, plus SQL standard. Clients are all running Windows XP pro.
Since the network was created, client has found that between 3:50PM - 4:10pm, the server and PC's will "pause" or lockup, and then after a couple of minutes resume working. No data seems to be lost, and machines generally don't crash, and the error happens daily around 4PM.
We have looked into scheduled tasks, checked event logs - there are no entries recorded in the event log during the lockup period, and checked for virus' and spyware. I have connected a PC to the network that isn't part of the domain, and it doesn't have any problems.
I have confirmed that group policy refreshes every 15-30 minutes, plus time sync happens every 90 minutes too. Windows updates don't seem to happen during this period either. We have connected a traffic monitoring program called SolarWinds, and less than 1% or the gigabit network is utilized during the freeze up period.
Any ideas anyone?