We’ve add a Server 2012 R2 as a domain controller to an existing SBS 2008 controller that we want to take out of circulation. The problem is, all the devices are still looking at the old server as their logonserver. The process of promoting the new server to a DC appeared to go smoothly, all AD, DHCP, GP settings appear to have been replicated, yet when we shut down or unplug the old 2008 server from the network, all the devices are slow to logon & operate because all are struggling to find their logonserver. Strangely when the new server is shut down, the internet doesn’t work because it has control of DHCP/DNS, so we seem to be in a bit of limbo where the new server is controlling some stuff but not others.
Our understanding is that there is no longer any such thing as a Primary or Backup DC, that there are simply domain controllers & devices will use whichever one is available, so why aren’t our devices switching over to the new controller when the old one is shut down? What processes are necessary after the promoting of a server to DC? We tried using NTSDUTIL to seize control, but that didn’t progress things at all.
I'll admit my IT skills are not quite up to this task, but I have a consultant helping me who's way more clued up, he just hasn't ever done this particular job before. I'm really reluctant to get in outside help, especially as we feel we're only missing something quite small. Any suggestions?