DHCP quit working

[Linthade]

I have a Windows 2000 server SP4 that the DHCP server has simply quit handing out addresses. I have uninstalled, reinstalled, started/stopped the service, recreated scopes and just about anything I could imagine.

It just will not hand out addresses. I'm not sure what I have left for options here short of nuking the system for a clean start (feared). Any ideas?

*lin*

[futuretech]

Is the DHCP server part of a Domain and if so is it or has it lost authorization from the DC'S

[CJK]

To go along with future tech, have you recently changed the server's IP address? If you did then you probably need to unauthorize your dhcp server under the old IP address and authorize the dhcp server under the new IP address.

You could also have a corrupt database. To fix this you need to stop the DHCP service and remove all of the files from %systemroot%\system32\DHCP, and then restart the service. Once you've done so, you can reconcile the scope to rebuild the database contents. The way you reconcile a scope is after you started the DHCP service open the DHCP snap-in. Expand the target server's node in the MMC until you see the target scope. Right-click the tartget scope and choose the Reconcile command. The Reconcile dialog box appears, but it's empty. To start the reconciliation, click the Verify button and follow the instructions thereafter.

[corturbra]

Also check that the culprit is not another DHCP server on the network taking over.....

for some reason in 2000/2003, windows will allow another DHCP server to take priority. Check that there is not a router firing out addresses.

[Linthade]

The Lan-side IP of the server has not changed. However, there is a small router on the lan that had it's public IP addressed changed from static to dynamic. The problem seemed to have started about that time.

I have verified that that router is not running DHCP. When I have the DHCP on the server enabled and with a scope activated, no DHCP services are answering on the lan for the workstations. So its reasonable to assume that there are no renegade DHCP services out there fouling up the server. They end up with one of the autoassigned IP's from windows built in service in the 169 range.

I now have the router offering DHCP so the workstations can function, but the server still isn't doing its job when configured to do so. I haven't been able to go back to the machine yet to try clearing the DCHP folder, will try that next.

*lin*

[corturbra]

The Lan-side IP of the server has not changed. However, there is a small router on the lan that had it's public IP addressed changed from static to dynamic. The problem seemed to have started about that time.

I have verified that that router is not running DHCP. When I have the DHCP on the server enabled and with a scope activated, no DHCP services are answering on the lan for the workstations. So its reasonable to assume that there are no renegade DHCP services out there fouling up the server. They end up with one of the autoassigned IP's from windows built in service in the 169 range.

I now have the router offering DHCP so the workstations can function, but the server still isn't doing its job when configured to do so. I haven't been able to go back to the machine yet to try clearing the DCHP folder, will try that next.

*lin*

Mmmm does seem a bit weird, try the clearing of DHCP if that fails try a different network card in the server if you can... how many clients need to be serviced by the DHCP server, or to put it better.... how big is your IP Scope?

Is there only one Network card in the server, 2000 can get upset about more than one card sometimes as it's not sure which card it should bind to.

Have you moved scopes at all? Done anything to change the DHCP config at all?

Anything been done to the PC's?

Article below explains how to sort out corrupted DHCP Databases, just in case you need it.
http://support.microsoft.com/default...roduct=win2000

What messages are in event viewer on PC's/Server regarding DHCP?

EDIT: Also I take it you've checked that the DHCP Server services are running, I have seen it where the DHCP console says it is authorised but the actual service itself wasn't?