active directory - DNS Resoluition of Child Domain Workstation(s)

I have three domain controllers:

DC-01 = CORP.LOCAL
DC-02 = A.CORP.LOCAL

DC-03 = B.CORP.LOCAL

All three have replication set to All DNS servers in the forest and I can see all three zones in each controller's DNS consoles.

I've added a workstation, PC-001, to A.CORP.LOCAL, but I can't ping it from CORP.LOCAL because it's not resolving the name. What am I missing? I thought now that all zones can see each other I can ping all machines from wherever by name? On that note, A and B can ping each other and CORP by name, but CORP can't ping either.

I can obviously cheat with CNAMEs in the CORP controller, but that's just silly to do for all the machines I'll be joining. I'd appreciate any pointers on how to get this to work.

For reference this is a Windows Server 2012 domain and forest running on Amazon EC2.

Answer

You need to add the necessary domain suffixes to the search list on all DNS clients (which is every machine; even DNS servers are also DNS clients.)

http://support.microsoft.com/kb/275553