I’ve run into the situation several times in the past where you deauthorize a DHCP server/scope, but when you click on “Add Authorized” server in your DHCP MMC snap-in, it still lists the old servers. I’ve found the quickest and most efficient way to remove these servers is using ADSIedit.
- Click start, in the search box type MMC and hit enter.
- On the console screen that pops up, add ADSIEdit to your list of snap-ins.
- Right Click “ADSI Edit” and select “Connect to…” from the menu.
Leave all defaults except the “Select a wekk known Name or Naming Context”. Hit the drop down arrow and select Configuration and then click OK:
Drill down to CN=NetServices and highlight it:
Double click on CH=DhcpRoot.
- Scroll down until you find the dhcpServers attribute. Double click on that attribute and remove the offending servers from the value field. Apply and close and you’re done!