• ESXi/ESX hosts intermittently disconnect or show as not responding in vCenter Server.
• The affected hosts reconnect or start responding automatically after 1-2 seconds.
• The Windows System Event log reports an event similar to:
  
  
  Information,"1","08/17/2011 00:52:45","Microsoft-Windows-Kernel-General","0","NT AUTHORITY\LOCAL SERVICE","The system time has changed to ‎2011‎-‎08‎-‎17T00:52:45.288902500Z from ‎2011‎-‎08‎-‎17T01:00:21.459104800Z."

To resolve this issue:

1. Configure time sync on the ESXi/ESX host. For more information, see Guide to configure NTP on ESX servers (1003063).
2. Configure time sync for vCenter Server and ensure that the W32time service is configured correctly. For more information, see the Microsoft Knowledge Base article 816042.