Global catalog is a feature in Microsoft Active Directory systems that contains searchable, partial representation of every object in every domain within a multi-domain Active Directory forest.

How Does a Global Catalog Work?

Global catalog does not store the entire attributes of every object but contains a subset of the most popular attributes such as a user’s login name, first and last name, and some other essential attributes. This enables the GC to respond seamlessly without consulting the domain controller responsible for the entire object.

The global catalog is mirrored across multiple global catalog servers (GCS). Active Directory’s multi-master replication mechanism manages this process, ensuring up-to-date and consistent data.

GS servers advertise their availability to domain controllers through the Directory replication service (DRS). So, a system or device will know where to find an available server whenever it needs to query the GC.

Global Catalog Uses

Examples of Global Catalog