The Global Catalog (GC) in Windows 2000 Active Directory (AD) is widely misunderstood and it's no wonder why: The catalog serves multiple purposes, has tons of features, and houses dissimilar forms of data. To understand the GC, you must first understand the concept of a "forest." A forest is a collection of one or more AD trees organized as peers and connected by two-way transitive trust relationships between the root domains of each tree. All trees in a forest share a common schema, configuration, and GC.

Eve...