When you run DCPROMO to promote a Windows Server to a replica domain controller, you receive:
The operation failed because: The directory service failed to replicate off changes made locally. The DSA operation is unable to proceed because of a DNS lookup failure.
When you check, the Windows Server properly points to the preferred DNS server for the domain.
The preferred DNS server must allow dynamic updates and it must support SRV resource records.
NOTE: After DNS is properly configured, you can set up forwarders to point to your ISP's DNS servers.