Solved

Problem with Kerberos not working until Domain Controller is rebooted

Posted on 2008-06-25
7
278 Views
Last Modified: 2008-07-17
We have set up Kerberos so that we can hop between SharePoint 2007, ProClarity and a SQL server without forcing users to re-authenticate. Most of the time this works fine. However we are seeing an issue where Kerberos stops working and the application passes along anonymous login - and of course we don't allow anonymous access to our databases so this fails. We have found that rebooting one of our domain controllers (Windows Server 2003) (that also happens to be our global catalog server) we can make this issue disappear - for a limited amount of time. I dont' see anything obvious in the logs. I have run a dcdiag on the domain controller - everything passes. I have suspected for some time that we were having issues with this server but have nothing solid to point at. Can anyone give me some ideas of what to look for? Are there any additional tests I can run on this server?

Thanks in advance,
Michelle
0
Comment
Question by:mrbarr87
  • 4
  • 3
7 Comments
 
LVL 23

Expert Comment

by:TheCleaner
ID: 21879147
No Kerberos errors in the system log on the DC?  Is that the only DC?  Can you shut it down for a day or two and see if everything works without that DC online?
0
 

Author Comment

by:mrbarr87
ID: 21879344
No kerberos errors in the logs. No we have another DC. I can't shut it down because it's our global catalog - exchange would be very unhappy without it. We are considering throwing up a third dc and making it a GC to see if things get happier - any reason not to do this?
0
 
LVL 23

Expert Comment

by:TheCleaner
ID: 21879397
Just make your other DC a GC as well...why would you need a 3rd one?
0
Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

 

Author Comment

by:mrbarr87
ID: 21908761
If we are going to shut down the 2nd domain controller, we would want to have another one up in its place. Since the problems are intermittent, we don't know how long it will be before we see the issue again.

Is there anything else to look for in troubleshooting kerberos issues? Any tests?
0
 
LVL 23

Expert Comment

by:TheCleaner
ID: 21908810
There are command line tests to see what tickets are open, etc.

http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/security/tkerberr.mspx

It talks about where to get klist and kerbtray and others to do troubleshooting.  Problem is, based on what your original description was, I'm not sure how good the tools will do you.

If nothing else, it may point out whether it really is a kerberos issue or not.
0
 

Author Comment

by:mrbarr87
ID: 21908842
Hmm good point. I guess my question then should be, other than taking the GC down - is there a way to test that DC? I did run the dcdiag - but everything came up clean - of course at that time we weren't experiencing the problem. Are there specific tests for gc? Or just wait until the error happens again then run the dcdiag?

Thanks for your time!
0
 
LVL 23

Accepted Solution

by:
TheCleaner earned 500 total points
ID: 21908919
To enable Kerberos logging navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\Kerberos\Parameters. Then set the DWORD value for LogLevel to one. Making this change logs the events to the System event log.

^^ try that on the DC(s) and set your system event log to have a big enough size to handle the events.  Then watch for times when the errors occur and see if they correspond to events in the log.  This should log all the kerberos events, even successful ones, so it should be apparent if there really is an issue or not at that point.

If you could always reproduce the issue, I'd say a network trace during the issue would be the way to go, but if it's sporadic it's going to be hard to go that route.
0

Featured Post

Netscaler Common Configuration How To guides

If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Find out how to use Active Directory data for email signature management in Microsoft Exchange and Office 365.
In this article, I am going to show you how to simulate a multi-site Lab environment on a single Hyper-V host. I use this method successfully in my own lab to simulate three fully routed global AD Sites on a Windows 10 Hyper-V host.
This tutorial will walk an individual through the steps necessary to join and promote the first Windows Server 2012 domain controller into an Active Directory environment running on Windows Server 2008. Determine the location of the FSMO roles by lo…
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.

820 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question