Windows 2000 Active Directory and domains

Many administrators have found user management in Windows NT awkward, especially in large organizations. In the past, NetWare had the preferred method of account management for large numbers of user accounts. For this reason, Microsoft introduced its new approach to user and account management in Windows 2000 platforms-Active Directory. Active Directory is a cornerstone concept for Windows 2000 because it significantly affects the layout and makeup of a Windows 2000-based network.

Active Directory allows network objects such as users and groups to be placed into logical areas of a database. This database can then be distributed among various servers, all of which participate in the Active Directory structure. Because all the network object information is placed in a single database, albeit a distributed one, it can be used by any network application or subsystem, eliminating the need for duplicate information.

Active Directory obviates the old Windows NT PDC and BDC network layout. Instead, servers on a Windows 2000 network can either be domain controllers or member servers. Domain controllers are servers that have Active Directory installed and configured on them. Domain controllers store user account information and provide network authentication. Unlike a Windows NT domain, which can have only a single PDC, a Windows 2000 domain can have several domain controllers, with each one having a read/write copy of the Active Directory database. For fault-tolerant reasons, this is a good strategy to employ.

Note Active Directory is a complex subject, and the information presented here is only intended as a brief overview. For the Network this is all that is needed, but for the real world you will need to do more studying. For further information on Active Directory, refer to Microsoft's Web site (www.microsoft.com).

Member servers are not involved in the authentication of network users and do not take part in the Active Directory replication process. Member servers are commonly employed as file and print servers, or with additional software, as database servers, firewalls, or servers for other important network services.