Windows 2000 Administration in a Nutshell

Name

global catalog

Synopsis

A feature of Active Directory designed to speed the process of performing search queries on Active Directory.

Description

The global catalog contains:

• A full replica (all attributes) of all objects in its own domain

• A partial replica (most commonly searched attributes) of all objects in other domains in the forest

The purpose of the global catalog is to help speed up search queries issued against Active Directory, especially tree- or forest-wide queries. This is because a multidomain query can be resolved by accessing a single domain controller (the global catalog server) instead of accessing a different domain controller in each of the queried domains.

The global catalog also supports the network logon process in native-mode domains by supplying a user’s membership information in universal groups to the domain controller the user tries to log on to. If the global catalog is not available in a native-mode environment, users will not be able to log on to the network (they can only log on to their local computers). Because of this, in a multisite environment it is a good idea to have at least one global catalog server in each site, especially when the WAN links between sites are slow or unreliable.

Global Catalog Server

By default, the first domain in the forest (forest root domain) is designated a global catalog server, and the global catalog is created automatically on this server. Other domain controllers can be configured to host the global catalog, and you ...