|Forest functional level||Available features||Supported domain controllers|
|Windows 2000 native||All of the default AD DS features are available.||Windows Server 2008|
Windows Server 2003
|Windows Server 2003||All of the default AD DS features, and the following features are available:|
- Forest trust
- Domain rename
- Linked-value replication - Linked-value replication makes it possible for you to change group membership to store and replicate values for individual members instead of replicating the entire membership as a single unit. Storing and replicating the values of individual members uses less network bandwidth and fewer processor cycles during replication, and prevents you from losing updates when you add or remove multiple members concurrently at different domain controllers.
- The ability to deploy a read-only domain controller (RODC)
Improved Knowledge Consistency Checker (KCC) algorithms and scalability
The intersite topology generator (ISTG) uses improved algorithms that scale to support forests with a greater number of sites than AD DS can support at the Windows 2000 forest functional level. The improved ISTG election algorithm is a less-intrusive mechanism for choosing the ISTG at the Windows 2000 forest functional level.
The ability to create instances of the dynamic auxiliary class named dynamicObject in a domain directory partition
The ability to convert an inetOrgPerson object instance into a User object instance, and to complete the conversion in the opposite direction
The ability to create instances of new group types to support role-based authorization.
These types are called application basic groups and LDAP query groups.
Deactivation and redefinition of attributes and classes in the schema
|Windows Server 2003|
Windows Server 2008
|Windows Server 2008||All of the features that are available at the Windows Server 2003 forest functional level, but no additional features are available. All domains that are subsequently added to the forest, however, operate at the Windows Server 2008 domain functional level by default.||Windows Server 2008|