Windows Server 2016 - DNS/AD problem

[ramon82]

Windows Server 2016 - DNS/AD problem

Hi all - at one point our DC froze and we had to do a restart. It installed a lot of updates and then once it got up and running again we started experiencing problems with DNS, passwords, mapped drives etc - please refer to screenshots. Its as if the communication between the desktops and the server got out of sync somehow.

Any idea what we can do please?

Thank you

[ramon82]

Hi again i discovered that this seems to be an AD issue through event viewer:

The Security System has detected a downgrade attempt when contacting the 3-part SPN 

 ldap/JUPITERDC01.jupiter.local/jupiter.local@JUPITER.LOCAL 

 with error code "The attempted logon is invalid. This is either due to a bad username or authentication information.
 (0xc000006d)". Authentication was denied.

Any ideas??

[NIM]

Hmm, strange. I've never experienced this kind of issue. For a start, I would try to demote this DC, remove it from the domain, delete the computer object, add it back to the domain, and then promote it to a domain controller.

After that see if everything is working fine.

Br