Modes Supported by Windows 2000 Domain Controllers

This article describes the two modes of operation supported by Windows 2000 domain controllers.

Windows 2000 domain controllers can operate in two different modes. These modes are Mixed and Native. Mixed mode provides compatibility with Windows NT 4.0 backup domain controllers (BDCs). Native mode provides additional functionality added in Windows 2000 if no Windows NT 4.0 primary domain controllers (PDCs) or BDCs are present.

Note that the process of converting from Mixed to Native mode is a one-way operation. After a domain uses Native mode, it cannot later be switched back to Mixed mode.

In an existing Windows NT 4.0 domain structure, the PDC must be upgraded to Windows 2000 first. While the PDC is operating in Mixed mode, two replication methods exist:

• For all Windows NT 4.0 BDCs, the Windows 2000 PDC replicates partial changes to the Windows NT 4.0 BDCs using the same method as is used in a Windows NT 4.0-only domain.
• All of the Windows 2000 domain controllers participate in multiple- master replication. Both secure and non-secure principals can be created on any Windows 2000 domain controller in the domain.

When a domain is converted to Native mode, Windows NT 4.0 BDCs no longer receive replication update changes and no Windows NT 4.0 BDCs can be added to the domain. Native mode allows for a new user group type (the Universal group). Group nesting allows nesting such as Global groups within Global groups, and Domain Local groups within Domain Local groups.

Windows 2000 member servers have use of Domain Local groups from the domain on the local computer. These Domain Local groups can be used to assign permissions and rights on the member server.