I have a recovery situation that I am currently trying to rectify. We had a data store fill up on a SAN, bringing down all VMs within that Datastore. We just recently brought both our primary and secondary Windows Server 2012R2 domain controllers online. Upon doing so we are unable to connect to the domain. We're presented with the error "Naming information cannot be located because: The specified domain either does not exist or could not be contacted". Whats odd is for a brief period, the domain connected back on both DCs then disappeared again. This made us think it was a DNS related issue, but we're able to ping both DCs from each other using hostname and FQDN.