We are running a Windows Environment, with Server 2003 Enterprise and Standard, with XP and Vista Machines. A week ago, our Primary Domain Controller (also was all the other operation and schema masters, with Global Catalog, and ran DNS and DHCP) stopped DHCP. We assessed the issue and fired DHCP up on another Domain Controller. When looking thru the Event Logs, there was no reason why DHCP failed, furthermore, it would not start up again.
At this point, it was an inconvenience. Like every other IT department we are underfunded and undermanned so we gave it a band-aid and moved on.
This week, we were trying to replace the server that DHCP had failed on, since it was going to be quicker to replace it than fix it. At this point, we believed that it was still functioning on every level beside DHCP, and had no reason to worry. We were wrong. We tried to remove it from the AD environment, and move its services around, correctly. I say "correctly" because later I learned that you are not supposed to have you Infrastructure Master and Global Catalog on the Domain Controller. Oops. But, we were shocked to see that the Domain Controller we will call it DC-01 was not available. The other Domain Controllers were all there. since then, I have tried all sorts of help documents on forcing server roles around, and now I'm afraid we just have a bit of a mess. I write a out a quick list of what we are dealing with.
DC-01 (formerly it was all the masters, and had Global Catalog) also running DHCP and DNS
DC-02 just Global Catalog and DNS
DC-03 just a Domain Controller, no Global Catalog
Exchange Server - Running with Domain Controller with Global Catalog (runs Exchange 2007)
I have 2 brand new clean Servers getting loaded up with Windows Server 2003 Standard R2 right now to be the main Domain Controllers, so we can get this all cleaned up, and old boxes (DC-02 and DC-03) laid to rest, as far as being Domain Controllers.
I think that is it. Worst case Scenario I will call Microsoft and pay thru the nose to have them slowly hold my hand and walk me thru everything. But, I have better things to do.