This policy setting allows you to control the domain controller (DC) location algorithm. By default the DC location algorithm prefers DNS-based discovery if the DNS domain name is known. If DNS-based discovery fails and the NetBIOS domain name is known the algorithm then uses NetBIOS-based discovery as a fallback mechanism.NetBIOS-based discovery uses a WINS server and mailslot messages but does not use site information. Hence it does not ensure that clients will discover the closest DC. It also allows a hub-site client to discover a branch-site DC even if the branch-site DC only registers site-specific DNS records (as recommended). For these reasons NetBIOS-based discovery is not recommended.Note that this policy setting does not affect NetBIOS-based discovery for DC location if only the NetBIOS domain name is known.If you enable or do not configure this policy setting the DC location algorithm does not use NetBIOS-based discovery as a fallback mechanism when DNS-based discovery fails. This is the default behavior.If you disable this policy setting the DC location algorithm can use NetBIOS-based discovery as a fallback mechanism when DNS based discovery fails.
System\Net Logon\DC Locator DNS Records
Machine
At least Windows Server 2012 Windows 8 or Windows RT
HKLM\Software\Policies\Microsoft\Netlogon\Parameters!AvoidFallbackNetbiosDiscovery
NetLogon.admx