A company uses ClearPass with Active Directory as both the authentication and authorization source.

In a standard AAA workflow, Authentication verifies the user's identity (credentials), while Authorization retrieves the metadata needed to decide what they can access. Using Active Directory for both roles is highly efficient; it allows ClearPass to confirm the password is correct and immediately pull group memberships and other user-specific attributes in a single logical process. This provides the "Rich Context" required to build granular enforcement policies.