1.3.1 Background

The Group Policy Protocol, as specified in [MS-GPOL], allows clients to discover and retrieve policy settings created by domain administrators. These settings are persisted within Group Policy Objects (GPOs) that are assigned to policy target accounts in the Active Directory. Policy target accounts are either computer accounts or user accounts in the Active Directory. Each client uses Lightweight Directory Access Protocol (LDAP) to determine what GPOs are applicable to it by consulting the Active Directory objects corresponding to each client's computer account, and the user accounts of any users logging on to the client computer.

On each client, each GPO is interpreted and acted upon by software components known as client-side plug-ins. The client-side plug-ins responsible for a given GPO are specified using an attribute on the GPO. This attribute specifies a list of globally unique identifier (GUID) pairs. The first GUID of each pair is referred to as a client-side extension GUID (CSE GUID). The second GUID of each pair is referred to as a tool extension GUID.

For each GPO that is applicable to a client, the client consults the CSE GUIDs listed in the GPO to determine which client-side plug-ins on the client will handle the GPO. The client then invokes the client-side plug-ins to handle the GPO.

A client-side plug-in uses the contents of the GPO to retrieve settings specific to its class in a manner specific to the class. Once its class-specific settings are retrieved, the client-side plug-in uses those settings to perform class-specific processing.