If you find the below message appearing within your server event log. There are different techniques to use when trying to resolve this issue but one which worked for me, was to enter the dns details into the domain controller the server was trying to replicate with. You may also want to run dcdiag. The dcdiag command line tool analyzes the state of domain controllers in a forest or enterprise and reports any problems to assist in troubleshooting.
Source: NTDS Replication
Event ID: 1864
Description: This is the replication status for the following directory partition on the local domain controller.
The local domain controller has not recently received replication information from a number of domain controllers. The count of domain controllers is shown, divided into the following intervals.
More than 24 hours:
More than a week:
More than one month:
More than two months:
More than a tombstone lifetime:
Tombstone lifetime (days):
Domain controllers that do not replicate in a timely manner may encounter errors. It may miss password changes and be unable to authenticate. A DC that has not replicated in a tombstone lifetime may have missed the deletion of some objects, and may be automatically blocked from future replication until it is reconciled.