Need help removing duplicate DHCP server on authoizied DHCP Server list

Help! Last night we had to re-IP one of our Windows 2003 Domimain Controllers that is running DHCP. After changing the DNS entry for the DC and changing the IP address on the DC we were able to go to our ROOT DC and add the Server with its new IP address to the list of authorized DHCP server but when we selected the entry for the DC with the old IP address and pressed "unauthorize", a message appeared on the screen saying that there was no object on the server. So what we have now is two entries in the DHCP authorized server list for the same server name but with different addresses and I can't remove the old one through the MMC or with NETSH. We would REALLY like to get rid of the entry with the old IP address. Can anyone tell me how I might get rid of this bogus entry? Thanks.

I thought I would add something to my own post. Not sure of the root problem but apparently when we change IP addresses in DNS and on the server itself, something got hosed up inside Active Directory and the only way to fix the issue was to go into ADSIEDIT.MSC and manually remove entries. The symptoms we observed inside ADSIEDIT was the fact that we had an old entry that contained the FQDN as part of the distinguished name and a new, second entry that contained the server's IP address in place of the FQDN as part of the distinguished name in Active Directory. To get things corrected we had to delete entries in AD using ADSIEDIT and also through the DHCP Authorized Servers applet to remove both the old and new entries and then re-add the server to the approved DHCP servers list. When we cleared all traces of the server from Authorized Servers applet we were then able to re-add the server to the approved servers list and this time the server was correctly added so the FQDN was a part of the distinguished name. When using the ADSIEDIT. MSC applet we had to drill down withing CONFIGURATION and then inside CN=Services then down inside CN=NETServices. At this point this is where we saw the entry containing the FQDN and a second entry containing the IP address under the name column.



If anyone else has a better understanding of why this is happening on an IP address change I would appreciate any additional information as to how one might be able to prevent it from happening again.