The network was fine yesterday and as far as I know nothing has been changed or added. This morning some computers are connected to our domain but most of them are reporting limited connectivity. On checking our DHCP server we are getting this message.
Cannot find the DHCP Server:
The DHCP server you specified cannot be located. The DHCP server might be down, there might be a network problem, or the DHCP service might not be installed.
The Error was: The DHCP Server service is not running on target computer.
I had to temporary issue the PC's with a static IP for them to connect and continue to work.
This is when the issue appears to start -
Error Message:-
The processing of Group Policy failed. Windows could not obtain the name of a domain controller. This could be caused by a name resolution failure. Verify your Domain Name System (DNS) is configured and working correctly.
Error message for below:-
The DHCP service failed to see a directory server for authorization.
I have checked the DHCP server Services and they are started.
In addition I have noticed that the DHCP Server service is not listed under Task Manager - Services Tab, but is listed as started in Services.msc. Is this normal?
We could not find an exact reason why this has failed, however we did find out that the firewall was enabled which really did not help matters. After restarting the server it came back up and started to work as intended.