Administering Computer Accounts and Resources in Active Directory
Terms you'll need to understand:
- Domain Trees
- Domain Forests
- Computer accounts
- Run As feature
- Globally unique identifiers (GUIDs)
- Organizational units (OUs)
- Microsoft Management Console (MMC) 3.0
- Active Directory Users and Computers console
Techniques you'll need to master:
- Adding and removing computer accounts
- Prestaging computer accounts
- Using command-line tools for modifying Active Directory objects
- Using the Action Pane in the MMC 3.0
- Enabling full functionality for MMC 3.0
- Managing resources using the Run As command
Microsoft introduced Active Directory with the debut of Windows 2000 Server in February 2000. Active Directory provides a directory service for Microsoft-based networks in the same way that Novell Directory Services (NDS) provides a directory service for NetWare environments. For Windows Server 2003, Microsoft enhanced and refined Active Directory by making the directory service more flexible, more scalable, and more manageable than its Windows 2000 predecessor. Active Directory is a vital element in Windows Server 2003, and its many benefits can offer a compelling reason to upgrade, especially if you are coming from a Windows NT Server environment.
Understanding how to manage objects within Active Directory is critical for a successful deployment and reliable day-to-day operations of a Windows Server 2003 Active Directory–based network. In this chapter, we introduce you to Active Directory for Windows Server 2003. You'll discover how to add, remove, and manage computer accounts in Active Directory. Unfortunately, network administration doesn't always go smoothly, so you'll also learn about how to troubleshoot computer accounts in Windows Server 2003 and Active Directory.
Microsoft released Windows Server 2003 Service Pack 1 (SP1) on March 2004, as a major update. In December 2005, Microsoft published the R2 (Release 2) Edition of Windows Server 2003, in 32-bit (x86) and 64-bit (x64) versions. This chapter and this book covers all of these different permutations of the Windows Server 2003 operating system—the original Release to Manufacturing (RTM) version, SP1, and R2 in both the 32-bit (x86) and 64-bit (x64) flavors. The functionality and features covered in this book apply to all of these editions, except where noted.
Introduction to Active Directory
The many improvements to Active Directory encompass some of the major feature enhancements of Windows Server 2003. Active Directory is a replicated and distributed database that stores computer-related information such as usernames, passwords, phone numbers, addresses, email addresses, group names, and computer names, to name a few. Active Directory is called a directory service because it provides users and computers with the ability to look up information in a similar way that you look up information using a telephone book directory.
Special servers called domain controllers (DCs) are designated to store a copy of the Active Directory database, and these DCs are responsible for synchronizing the Active Directory database with all of the other DCs that share the database. Server computers, as well as workstation computers that are members of an Active Directory domain, perform several Active Directory queries (or lookups) in their day-to-day operations. For example, Active Directory domain-member computers need to know where nearby DCs are for authentication purposes.
Active Directory is based on open, Internet-related standards, such as the Transmission Control Protocol/Internet Protocol (TCP/IP), the Domain Name System (DNS), the Kerberos authentication protocol, and the Lightweight Directory Access Protocol (LDAP), among many others. In fact, you cannot install Active Directory without TCP/IP and DNS installed and functioning within the network environment. You must name Active Directory domains using a full DNS name such as examcram2.informit.com.
Domains, Domain Trees, and Domain Forests
A Windows Server 2003 computer (or a Windows 2000 Server computer) becomes a DC when an administrator runs the Active Directory Installation Wizard. You can run the wizard by clicking Start, Run; typing dcpromo.exe; and clicking OK. This process promotes a server to a DC. The wizard makes several changes to the server computer to prepare it to become a DC. One of the major changes is the creation of the Active Directory database file itself. This file is named ntds.dit, and it must reside on a hard disk partition or volume that is formatted as NTFS. The default location for the ntds.dit file is the %systemroot%\ntds folder (for example, c:\windows\ntds).
The very first Windows Server 2003 (or Windows 2000 Server) DC that you promote creates the root domain. For example, if you promote a DC and name the domain examcram2.net, this domain becomes the root domain within the new Active Directory forest. The basic logical components of Active Directory are as follows:
- Domain—One or more DC servers and a group of users and computers that share the same Active Directory database for authentication and can share common server resources.
- Domain Tree—One or more Active Directory domains that share a common hierarchical DNS namespace (parent-child-grandchild and so on). For example, examcram2.net could be the parent domain, northamerica.examcram2.net could be the child domain, us.northamerica.examcram2.net could be the grandchild domain, and so on.
- Domain Forest—One or more Active Directory domain trees (each tree has its own DNS namespace) that share the same Active Directory database. An Active Directory forest is a logical container for one or more related domains.
No Primary or Backup Domain Controllers
Windows NT Server 3.5x and Windows NT Server 4.0 used the concept of one primary DC (PDC) and backup DCs (BDCs), where only one of the DCs could act as the PDC at any one time. The PDC stores the read/write copy of the security accounts manager (SAM) database, whereas each BDC stores a read-only copy of the SAM database. Instead, Active Directory uses a technique called multimaster replication to distribute copies of the Active Directory database to all other DCs that share the same Active Directory namespace. This replication technology means that administrators can make additions, changes, or deletions to the Active Directory database from any DC, and those modifications get synchronized with all of the other DCs within an Active Directory domain and the GCs within the entire AD forest. Active Directory assigns the role of PDC Emulator to the first DC to come online in an Active Directory forest. The DC that has the PDC Emulator role can communicate between Active Directory and down-level PDCs and BDCs running on Windows NT Server 3.5x and Windows NT Server 4.0.
To improve network administration, Microsoft created organizational units (OUs) to provide for logical groupings of users, groups, computers, and other objects within a single domain. You can delegate administrative authority over each OU to other administrators for distributing network-management chores. The delegated authority can be limited in scope, if necessary, so that you can grant junior administrators just specific administrative powers—not complete administrator-level authority. In addition, you can apply specific group policy object (GPO) settings at the OU level, allowing users and computers to be managed differently according to the OU in which they are placed.
The Microsoft Management Console (MMC)
The MMC is the standard interface for hosting all of the various GUI tools and utilities that administrators use to manage the Windows and Active Directory environments. The MMC is a shell that houses MMC snap-ins—the snap-ins actually provide the functionality. The MMC provides a consistent and standardized look and feel for all the snap-in tools. MMC snap-in files use the file extension .msc. You can see several of the default snap-ins if you browse the %systemroot%\system32 folder on a Windows Server 2003 computer.
For example, on a domain controller, you can run the Active Directory Users and Computers (ADUC) snap-in by double-clicking the dsa.msc file in the %systemroot%\system32 folder. Alternatively, you can run the ADUC snap-in by clicking Start, Run, typing in dsa.msc, and clicking OK. You must include the .msc file extension for the snap-in to run. You also have the option of clicking Start, Run, typing in mmc, and clicking OK to display an empty console; you can then click File, Add/Remove Snap-in to load the snap-in(s) of your choice.
When you upgrade Windows Server 2003 to the R2 Edition, the MMC gets upgraded to version 3.0 automatically. The MMC 3.0 sports three major improvements over its previous versions:
The Action pane—The Action pane is displayed on the right side of the console when it is not hidden. (It is usually hidden by default on most snap-ins.) The Show/Hide Action Pane toolbar icon shown in Figure 2.1 is similar to the Show/Hide Console Tree toolbar icon. The Action pane displays the actions that can be performed on the currently selected item in the console tree (left pane) or in the results pane (center pane). You can view the same list of actions by right-clicking an item.
Figure 2.1 A view of the Action pane for the ADUC snap-in under MMC 3.0 and Windows Server 2003 R2.
- Enhanced Error Handling—MMC 3.0 notifies you when errors occur within loaded snap-ins that could cause the MMC shell to stop responding. When the MMC 3.0 detects an error, it offers you some options to deal with the error.
Improved Add or Remove Snap-in dialog box—The redesigned Add or Remove Snap-in dialog box for the MMC 3.0 makes it easier to add, remove, and organize snap-ins (see Figure 2.2).
Figure 2.2 The Add or Remove Snap-ins dialog box under MMC 3.0 and Windows Server 2003 R2.