Global Catalog

Simple definition

A domain controller role containing a partial copy of the forest objects.

Technical definition

The Global Catalog contains all the objects of its domain and a subset of attributes of the other forest domains.

What is it used for ?

Allow for global searches and some multi-domain authentications.

Practical example

Outlook or an application can search for objects throughout the forest via GC.

Common issues

• GC not available
• Incomplete replication
• Attribute not present in the partial attribute set

Key takeaway: Exact behavior and commands may vary depending on versions, products and architectures.