I just installed the NPS for the first time on our domain and authentication fails with message " There is no domain controller available for domain tp.dom" . We have two domain controllers and both are working fine. I ran nltest with various options and all the commands are successfully completed and finds the domain controllers.  Also I can login to NPS server using TP.DOM\username. I tried few different users and it's successfully. I am not sure why NPS can't locate the domain controller.

So I tried on a different machine and getting the same error. Both run windows 2008 R2. Our DCs are 2003 R2.

 Below is the message from NPS trace.

[5424] 07-08 18:54:32:124: Failed to connect to the cached DC, try DC locator ...
[5424] 07-08 18:54:32:124: Could not open an LDAP connection to domain TP.DOM.
[5424] 07-08 18:54:32:124: NTDomain::getConnection failed: The specified domain either does not exist or could not be contacted.
[5424] 07-08 18:54:32:124: Retrying LDAP search.
[5424] 07-08 18:54:32:124: Could not open an LDAP connection to domain TP.DOM.
[5424] 07-08 18:54:32:124: NTDomain::getConnection failed: The specified domain either does not exist or could not be contacted.
[5424] 07-08 18:54:32:124: No AUTHORIZATION extensions, continuing
[5424] 07-08 18:54:32:124: Added EAP Failure packet

Any help is appreciated.  - thanks.

Hi,

I tried few different users and it's successfully. Base on my experience, it seems that was cause by your NPS DNS configured incorrect or the connection between the NPS and DC was cashed.

The related solution:
Event ID 4402 NPS and Domain Controller Communication
http://technet.microsoft.com/en-us/library/cc735393(v=WS.10).aspx

Hope this helps.

 

Hi,

This might be an old thread, but it comes up high in search lists. The solution mentioned in this article didn't do it for me. It turned out I had to go in to the NPS console, right click NPS Server and click Register NPS server in Active Directory.

Hopefully this will help other people in the future.

Thanks

• Proposed as answer by enotsIT 5 hours 53 minutes ago

Herman Bonnie is correct. I setup a new RDS gateway to replace our old one and I needed to Activate the NPS Server in AD. Thank you!

Setting up a Remote Desktop Gateway I was getting this error. It was Herman Bonnie's solution that resolved it for me.