Server add error message!!!

I've just started prepping for 70-410 & I installed the 2012 datacenter in one pc with static IP & same subnet as the datacenter on another pc.....they both r on same network & subnet....ran dcpromo & added AD DS roles.......both servers show ojnline in their respective workstations......but when i try to add any one of em into another via server manager, i get a kerberos error message....can't seem to figure out what i'm doing wrong....can anyone help?
Comments
Need some clarification before I can accurately help.
Did you promote one or both servers to a Domain Controller, and if both are they in the same domain?
How are you trying to add them in Server Manager?
Anytime you have an error it always helps to include the exact error message with the question.
Also how are you trying to add them in Server Manager?
Have you followed the steps detailed here Add Servers to Server Manager for your specific scenario?
You probably don't have the right credentials to manage the other server(in the other domain) in Server Manager.
You prob want this link...
Windows Server 2012 - Server Manager Troubleshooting Guide, Part II: Troubleshoot Manageability Status Errors in Server Manager - TechNet Articles - United States (English) - TechNet Wiki
but you probably are making this really hard on yourself...
If I'm accurate then can I suggest you blow one DC away(or demote it), rebuild it as a normal server and join it to the domain that is left on the other server. Then you can use the same credentials in Server manager to have it appear.