Many features of AD behave differently based on whether the domain is in mixed or native mode. A Windows 2000 domain in mixed mode can have NT backup domain controllers (BDCs) present in the domain and can even add NT BDCs to the domain. On the other hand, a Windows 2000 domain in native mode has no NT BDCs and has been explicitly converted to native mode.
Even in mixed mode, Active Directory provides almost innumerable advantages over NT domains. Kerberos authentication, hierarchical management, delegation of authority, and group policy are still available to Windows 2000 clients and servers that belong to an Active Directory domain, even in mixed mode.
Every Windows 2000 domain is in mixed mode when it is first ...