Active Directory FAQ's

What is an Active Directory (AD)?

The Microsoft Windows 2003 Active Directory glossary defines an Active Directory as “a structure supported by Windows 2003 that lets any object on a network be tracked and located. Active Directory is the directory service used in Windows 2003 Server and provides the foundation for Windows 2003 distributed networks.” A directory service “provides the methods for storing directory data and making this data available to network users and administrators. For example, Active Directory stores information about user accounts, such as names, phone numbers, and so on, and enables other authorized users on the same network to access this information.”

The AD, or Active Directory, is a database based on the LDAP (Lightweight Directory Access Protocol) standard, which makes the information contained within the AD easily available to other applications across different platforms. The AD contains user accounts, computer accounts, organizational units, security groups, and group policy object - all of which have a unique name and a unique path. All unique objects in the AD use a domain contained within the AD as a means of authentication.

What is a domain?

The Microsoft Windows 2003 Active Directory glossary defines a domain as “a single security boundary of a Windows NT-based computer network. Active Directory is made up of one or more domains. On a standalone workstation, the domain is the computer itself. A domain can span more than one physical location. Every domain has its own security policies and security relationships with other domains. When multiple domains are connected by trust relationships and share a common schema, configuration, and global catalog, they constitute a domain tree. Multiple domain trees can be connected together to create a forest.”

What is a tree?

The Microsoft Windows 2003 Active Directory glossary defines a tree as “a set of Windows NT domains connected together through transitive, bidirectional trust, sharing a common schema, configuration, and global catalog. The domains must form a contiguous hierarchical namespace such that if a.com is the root of the tree, b.a.com is a child of a.com, c.b.a.com is a child of b.a.com, and so on.”

What is a forest?

The Microsoft Windows 2003 Active Directory glossary defines a forest as “a group of one or more Active Directory trees that trust each other. All trees in a forest share a common schema, configuration, and global catalog. When a forest contains multiple trees, the trees do not form a contiguous namespace. All trees in a given forest trust each other through transitive bidirectional trust relationships. Unlike a tree, a forest does not need a distinct name. A forest exists as a set of cross-referenced objects and trust relationships known to the member trees. Trees in a forest form a hierarchy for the purposes of trust.”

What is a schema?

The Microsoft Windows 2003 Active Directory glossary defines a schema as “the definition of an entire database; the universe of objects that can be stored in the directory is defined in

the schema. For each object class, the schema defines what attributes an instance of the class must have, what additional attributes it may have, and what object class can be a parent of the current object base.

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What is a global catalog (GC)?

The Microsoft Windows 2003 Active Directory glossary defines a global catalog (GC) as “the global catalog contains a partial replica of every Windows 2003 domain in the directory. The GC lets users and applications find objects in an Active Directory domain tree given one or more attributes of the target object. It also contains the schema and configuration of directory partitions. This means the global catalog holds a replica of every object in the Active Directory, but with only a small number of their attributes. The attributes in the global catalog are those most frequently used in search operations (such as a user’s first and last names, logon names, and so on), and those required to locate a full replica of the object. The GC allows users to find objects of interest quickly without knowing what domain holds them and without requiring a contiguous extended namespace in the enterprise. The global catalog is built automatically by the Active Directory replication system.”

What is an organizational unit (OU)?

The Microsoft Windows 2003 Active Directory glossary defines an organizational unit as “a container object that is an Active Directory administrative partition. OUs can contain users, groups, resources, and other OUs. Organizational Units enable the delegation of administration to distinct subtrees of the directory.”

What is a group policy?

The Microsoft Windows 2003 Active Directory glossary states that a group policy “refers to applying policy to groups of computers and/or users contained within Active Directory containers. The type of policy includes not only registry-based policy found in Windows NT Server 4.0, but is enabled by Directory Services to store many types of policy data, for example: file deployment, application deployment, logon/logoff scripts and startup/shutdown scripts, domain security, Internet Protocol security (IPSec), and so on. The collections of policies are referred to as Group Policy objects (GPOs).”

A group policy object (GPO) is defined as “a virtual collection of policies. It is given a unique name, such as a globally unique identifier (GUID). GPOs store group policy settings in two locations: a Group Policy container (GPC) (preferred) and a Group Policy template (GPT). The GPC is an Active Directory object that stores version information, status information, and other policy information (for example, application objects). The GPT is used for file-based data and stores software policy, script, and deployment information. The GPT is located on the system volume folder of the domain controller. A GPO can be associated with one or more Active Directory containers, such as a site, domain, or organizational unit. Multiple containers can be associated with the same GPO, and a single container can have more than one associated GPO.”

A GPO is broken into two major sections, the Computer Configuration and the User Configuration. The Computer Configuration holds policies that are relevant only to the machine itself. The Computer Configuration can control printers, network settings, Startup and Shutdown scripts. One of the more useful policies based under the Computer Configuration setting is the loopback policy, which allows User Configurations policies to be applied to a computer, regardless of the user (unless the user is denied the GPO). Under the

User Configuration, logon and logoff scripts can be configured, folders can be redirected, and security settings can be tweaked.

What is an access control list (ACL)?

The Microsoft Windows 2003 Active Directory glossary defines an access control list as “a set of data associated with a file, directory, or other resource that defines the permissions that users and/or groups have for accessing it. In the Active Directory™ service, an ACL is a list of access control entries (ACEs) stored with the object it protects. In the Windows NT® operating system, an ACL is stored as a binary value, called a security descriptor.”

What is an access control entry (ACE)?

The Microsoft Windows 2003 Active Directory glossary states that “each ACE contains a security identifier (SID), which identifies the principal (user or group) to whom the ACE applies, and information on what type of access the ACE grants or denies.”

P01 - Can we add a Server within Windows Server 2003 in a 2000 Domain ?

Yes, DC under Windows Server 2000 and Windows Server 2003 can cohexist.

Before doing this you have to prepare the AD schema ,with adprep /forestprep

P02 - How to name an AD domain ?