Microsoft® Exchange Server 2003 Unleashed

Defining the Global Catalog

The Global Catalog is an index of the Active Directory database that contains a partial copy of its contents. All objects within the AD tree are referenced within the Global Catalog, which enables users to search for objects located in other domains. Every attribute of each object is not replicated to the Global Catalogs—only those attributes that are commonly used in search operations, such as first name, last name, and so on.

Global catalog servers, commonly referred to as GCs or GC/DCs, are Active Directory domain controllers that contain a copy of the Global Catalog. Locating a minimum of one Global Catalog server in each physical location is a wise move, because the Global Catalog must be referenced often by clients, ...