From time to time I see old/orphaned objects in the DHCP Server authorized lists. This happens often when you change IP address and DNS is not resolving the old IP address.
When you try to unauthorize following error message appears:
There is no such object on the server.
What you need to do is removing some references in AD.
- Open Adsiedit
- Connect to “CN=NetServices,CN=Services,CN=Configuration,DC=Your Domain,DC=com”
- Expand, and then you should see CN = DhcpRoot.
- Edit dhcpServers attribute on DhcpRoot to reflect (delete the orphaned servers)
- Verify the Authorized list in DHCP