Question/Issue:
Why are Windows XP and Vista clients losing connectivity to Windows Server 2008 64-bit file shares and DFS shares?

Symptoms:
Windows XP and Vista clients lose connectivity to Windows Server 2008 64-bit file shares and DFS shares after a period of time when the server is under load during production hours. The Windows Server 2008 itself does appear to be working and does not show any signs of a deadlock. This issue was reported on Symantec Endpoint Protection MR3 and MR4.

Solution:
This problem is fixed in Symantec Endpoint Protection 11.0.4202.75 (MR4 MP2) or later, and the Windows 2008 operating system should be running Service Pack 2 or higher.

For information on how to obtain the latest build of Symantec Endpoint Protection, read Obtaining an upgrade or update for Symantec Endpoint Protection 11.x or Symantec Network Access Control 11.x:

http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2007121216494948

Document ID: 2008100113145148
Last Modified: 08/11/2009
Date Created: 10/01/2008
Operating System(s): Windows Server 2008 DataCenter 64-bit, Windows Server 2008 Enterprise 64-bit, Windows Server 2008 Standard 64-bit, Windows Server 2008 Web Server 64-bit
Product(s): Endpoint Protection 11
Release(s): Endpoint Protection 11.0.3, Endpoint Protection 11.0.4