A new 2012 Domain controller rebooted after being promoted , however on restart DNS server would not start with the follow error

 The DNS server is waiting for Active Directory Domain Services (AD DS) to signal that the initial synchronization of the directory has been completed. The DNS server service cannot start until the initial synchronization is complete because critical DNS data might not yet be replicated onto this domain controller. If events in the AD DS event log indicate that there is a problem with DNS name resolution, consider adding the IP address of another DNS server for this domain to the DNS server list in the Internet Protocol properties of this computer. This event will be logged every two minutes until AD DS has signaled that the initial synchronization has successfully completed.

Multiple sites online recommend a registry change to skip the initial replication , however this was production

Check the directory services event tab

This directory server has not completed a full synchronization of the following directory partition. This directory server will not available to clients until this task is completed.

Note , how big it your Sysvol + Netlogon + ntds.dit ? This will effect replication time!

The command will show this

repadmin /showrepl

In the end replication time won , it took 6 Hours!