Verify Global Catalog DNS Registrations
Applies To: Windows Server 2008, Windows Server 2008 R2
To verify that a server is advertised as a global catalog server, confirm the presence of Domain Name System (DNS) service (SRV) resource records for the server. You can use this procedure to verify global catalog DNS registrations.
Membership in DNSAdmins and the right to log on locally to the domain controller is the minimum required to complete this procedure. By default, members of Account Operators, Administrators, Enterprise Admins, Domain Admins, Backup Operators, Print Operators, and Server Operators have the right to log on locally to a domain controller. Review details about using the appropriate accounts and group memberships at Local and Domain Default Groups (https://go.microsoft.com/fwlink/?LinkId=83477).
To verify global catalog DNS registrations
Click Start, point to Administrative Tools, and then click DNS.
Connect to a domain controller in the forest root domain: Right-click DNS, click Connect to DNS Server, and then click The following computer. Type the computer name, and then click OK.
Expand Forward Lookup Zones, and then expand the forest root domain.
Click the _tcp container.
In the details pane, look in the Name column for _gc and in the Data column for the name of the server. The records that begin with _gc are global catalog service (SRV) resource records.