I've just installed a new Windows 2008 domain. I have two HP Proliant ML350 G6s with Xeon E5520 2.26 GHz processors. Both have HP branded Window 2008 Server 64-bit installed. One server, VMHost1, has two virtual servers running, VitServ1 (Win2k8 32-bit) and Vit Serv2 (Win2k3 SP3). VMHost2 has one virtual server, VitFile (Win2k8 32-bit).
VitServ1 and VitFile are Domain Controllers.
VitFile is a file server and an AV server running Symantec Endpoint Protection Manager Version 11.0.5002.333.
There are three users in this network, all using new HP desktops running Windows XP SP3.
The users have three mapped drives, H:, P:, and U:.
The problem is that sometimes it looks like one or two mapped drives are empty. Opening the P: will seems to work, but no files will be listed. After this, if they open H:, that drive is fine but still nothing listed on P:. Rebooting seems to fix this, but it happens ramdomly to different drives, and different users/computers.
I did see a couple of errors in the event logs on the XP machines saying that the number of TCP/IP concurrent connections have been reached, but the times don't match the problem.
I also have a few of Event ID: 2012: "While transmitting or receiving data, the server encountered a network error. Occassional errors are expected, but large amounts of these indicate a possible error in your network configuration. The error status code is contained within the returned data (formatted as Words) and may point you towards the problem."
I have found a similar problem related to Symanect Endpoint but it was supposedly fixed in an update, but the version I am running is later than the patched version.
This is all new equipment, from the servers, switch, cables, and desktops.