KDC Event ID 11 - Solved

If you are creating SPN records in AD and don't take pre-cautions, you may end with duplicate SPN records. This will prevent AD users from logging on to the machine.  Following event id is logged in event log.

Event Type: Error

Event Source: KDC
Event Category: None
Event ID: 11
Date: 4/11/2011
Time: 3:57:13 PM
User: N/A
Computer: DC00
Description:
There are multiple accounts with name cifs/devap02.abc.local of type DS_SERVICE_PRINCIPAL_NAME.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.


Event Type: Error
Event Source: KDC
Event Category: None
Event ID: 11
Date: 4/11/2011
Time: 3:31:53 PM
User: N/A
Computer: DC00
Description:
There are multiple accounts with name host/devap01.abc.local of type DS_SERVICE_PRINCIPAL_NAME.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Refer to this Micrsoft KB article to reslove this issue.
http://support.microsoft.com/kb/321044

Ad tools required are ldp.exe and adsi.msc.