Configuring a global catalog server

As we've mentioned, the global catalog server is a domain controller that holds a global catalog. By default, the first domain controller in the forest root domain is the global catalog server. If you have a multi-domain environment that needs to be more scalable for cross-forest queries, you need to implement more than one global catalog server.

Configuring the global catalog on the domain controller can be done using the Active Directory Sites and Services MMC Snap-in or PowerShell commands. If you want to do this using a GUI, you just need to open the properties of domain controller and check the global catalog checkbox:

Once you open NTDS properties, you will be able to promote the server to a Global Catalog server and also remove the Global Catalog role from the server:

Using PowerShell, you need to run one of the following commands:

Set-ADObject -Identity (Get-ADDomainController DC02).ntdssettingsobjectdn -Replace @{options='1'}
Set-ADObject "CN=NTDS Settings,CN=DC02,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=mcsacertguide,DC=local" -Replace @{options='1'}