I have a weird problem.
Background: I had 2003 sbs and migrated to 08R2. I demoted sbs and 08R2 worked just fine. I added domain services to 2012 R2 and clicked GC and moved the FSMO roles to the new 2012 R2 server. They both show up in ADUC under domain controllers. I can ping lf.local from any workstation and get the round robin reply from DNS.
Here's the problem. When I shutdown the 08R2 server, AD goes down too. I tried to run ADUC from my workstation and from the 12R2 server but they both say there are no directory servers available.
If I boot up the 08R2 server then all is well. I can manually change to 12R2 server in ADUC and it comes up fine while the 08R2 server is running also. My goal is to continue the migration from 08R2 to 12R2 and demote the 08R2 asap.
I've checked a million times everything in AD I can, and it all says both servers are domain controllers. DNS works fine. I modified an A record on 08R2 and it changed on 12R2. I then changed it back on the 12R2 and it changed on the 08R2. I changed the description field in a user and it changed both ways. Replication seems to be bi-directional and working. Plus I've check in ADSS a bunch too to make sure the replication is set correctly.
What did I miss on the 12R2 server? I'm not seeing my mistake.