I'm tring to replicate my primary DC with another DC on a different network. In AD Sites and Services I am getting the following error under NTDS Settings:
"The following error occured during the attempt to contact the donain controller: The RPC Server is Unavailable. This issue may be caused by a DNS lookup problem".
Also in the Event Viewer under Directory Service has the same NTDS error:
The local domain controller has not recently received replication information from a number of domain controllers.
Also, I can ping the new DC and primary DC so networking is not an issue.