This has become a real problem for a customer of mine. They are ready to cancel there service contract if I do not get is resolved. I have a SBS 2003 acting as a Domain Controller. There are 12 workstations all with XP Pro. Most of the time every thing is working well. What happens is the they will lose connection to the server. If they are working on a word document from a network folder the program will lock. They also use AutoCAD and if it happens when they are in a drawing it will lock up. This will not happen at the same time for each workstation. 1 can be locked up and the other is working fine. They say that it seems to happen at the end of the day between 4-5 pm. They have mouse movement and can open programs on the workstation. I checked the event viewer on the XP workstation and see:
The Security System detected an attempted downgrade attack for server cifs/Server. The failure code from authentication protocol Kerberos was "There are currently no logon servers available to service the logon request.
The Security System could not establish a secured connection with the server cifs/Server. No authentication protocol was available.
No Domain Controller is available for domain HARTCORN due to the following:
There are currently no logon servers available to service the logon request. .
Make sure that the computer is connected to the network and try again. If the problem persists, please contact your domain administrator.
I have checked
1. Power settings on the network cards
2. Log in times
3. Auto disconnect on the server
Thanks for the help