Designate a Domain Controller to Be a Global Catalog Server
Applies To: Windows Server 2008, Windows Server 2008 R2
You use this procedure to designate a domain controller as a global catalog server. When you designate a domain controller as a global catalog server, a partial, read-only directory partition for each domain in the forest, other than the full, writable directory partition of the local domain, is replicated to create the global catalog instance on the server.
Membership in Domain Admins, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at Local and Domain Default Groups (https://go.microsoft.com/fwlink/?LinkId=83477).
To designate a domain controller to be a global catalog server
Click Start, point to Administrative Tools, and then click Active Directory Sites and Services.
In the console tree, expand the Sites container, and then expand the site in which you are designating a global catalog server.
Expand the Servers container, and then expand the Server object for the domain controller that you want to designate as a global catalog server.
Right-click the NTDS Settings object for the target server, and then click Properties.
Select the Global Catalog check box, and then click OK.