Use DNS name resolution with a single-label domain name instead of NetBIOS name resolution to locate the DC This policy setting specifies whether the computers to which this setting is applied attempt DNS name resolution of a single-label domain names. By default, when a computer (or the DC Locator running on a computer, to be more specific) needs to locate a domain controller hosting an Active Directory domain specified with a single-label name, the computer exclusively uses NetBIOS name resolution, but not the DNS name resolution, unless the computer is joined to an Active Directory forest in which at least one domain has a single-label DNS name. If you enable this policy setting, computers to which this policy is applied will attempt to locate a domain controller hosting an Active Directory domain specified with a single-label name using DNS name resolution. If you disable this policy setting, computers to which this setting is applied will only use NetBIOS name resolution to attempt to locate a domain controller that hosts an Active Directory domain specified with a single-label name. the computers will not the DNS name resolution in this case, unless the computer is searching for a domain with a single label DNS name that exists in the Active Directory forest to which this computer is joined. If you do not configure this policy setting, it is not applied to any computers, and computers use their local configuration.

[enable/disable]

(1) GPO: Computer ConfigurationAdministrative TemplatesSystemNet LogonDC Locator DNS Records!Use DNS name resolution with a single-label domain name instead of NetBIOS name resolution to locate the DC (2) REG: HKEY_LOCAL_MACHINESoftwarePoliciesMicrosoftNetlogonParameters!AllowSingleLabelDnsDomain