While validating a Failover Cluster over two member servers I get the following two errors:
- Connectivity to a writable domain controller from node SQL2.domain.com could not be determined because of this error: Could not get domain controller name from machine SQL2.
- Node(s) SQL2.domain.com cannot reach a writable domain controller. Please check connectivity of these nodes to the domain controllers.
If I run the Failover Cluster from SQL2.domain.com I get the same errors about SQL1.domain.com .
I have disabled IPv6 on the DC and SQL1/2, rebooted the servers after each attempt and removed/rejoined the member servers in the domain and nothing worked.
Both servers use only one DNS server which is the DC and the DC has public DNS servers setup in the forwarders list. This is a vanilla installation with no Firewall, DNS or LDAP changes.
From both member servers I can perform nslookup on the domain name and domain controller FQDN and it's responding for ICMP.