Jump to content

Windows Server 2016 - DNS/AD problem


Recommended Posts

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



Link to comment
Share on other sites

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 


 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??

Link to comment
Share on other sites

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.


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...