What Is a Directory Service?

Directory services work for the network just as white pages do for the telephone system. Directory services store information about things in the real world, such as people, computers, printers, and so on, as objects with descriptive attributes. People can use the service to find objects by name or just use the Yellow Pages to find services.

There are various types on the Internet, especially the Internet

Directory services are services that make all the information and resources in the directory useful, such as user and resource management, directory-based network services, and network-based application management!

Directory format

The table of contents is the map of the reader. It provides an overview of the content of the document and helps readers quickly find specific chapters.

The table of contents can be a simple list of chapter titles, or it can include multiple titles or

Directory services are one of the most important components in an extended computer system. Although users and administrators often don't know the exact name of the object they are interested in, they may know one or more attributes of that object, and they can query the directory to get a list of objects that match those attributes.

Directory services can:

Enforce security as defined by the administrator to keep the information safe from intruder attacks.

· Distribute directories among multiple computers on a network to provide higher performance.

· Copy the directory so that more users can use the directory, while effectively preventing failures.

Dividing the directory into multiple

As the number of objects on the network grows, directory services become more and more important. Directory services are like a central point, and a large distributed directory operates around the center.

In the past, directory services were primarily used to name and locate network resources. These features have now been extended, and directory services have become an important component within the Internet / Intranet infrastructure, providing services like reference directories, white and yellow pages, and email directories.

The directory service is also enabled in different

Directory services are powerful search tools for finding users and business partners worldwide. Address book supports LDAP (lightweight

The X.500 inverted hierarchy tree is shown in Figure D-24. Directories are called containers or

In this scenario, no additional directories are created. Instead, management applications allow administrators to work directly with individual directories by providing a single view of the directory through an index mapping pattern. Entevo uses this method.

The most important directory services ^[1] are described below. Microsoft Active Directory Novell NDS is the two main directory services. Active Directory runs only with Windows 2000, and NDS has been ported to various platforms. A significant difference between them is that in the case of NDS, all access control is managed by the directory: but in the case of Windows 2000, some access control is in Active Directory, while other access control is in the server. NDS follows the more traditional X.500 model, while Active Directory still has elements of the Microsoft domain model (a proprietary scheme).

The DCE directory service is used to maintain information about various distributed resources (such as users, machines, DCE RPC-based distributed applications, etc.), including the name and location of the resource. The Open Group's DCE (Distributed Computing Environment) includes its own directory service that integrates with other DCE components.

IBM Network Directory IBM's entry into the directory services market relies on its DB2 database. The database is designed for e-commerce and business-to-business transactions. IBM claims the service is more secure and scalable than Novell's NDS and Microsoft's Active Directory.

Netscape Directory Server NetscaPe's Directory Server is designed to be a central place to add, modify, and delete user information. It organizes and distributes information on a series of servers across the corporate intranet. These services can be integrated with Netscape's SuiteSpot to provide structured information and combined information for a complete set of applications. Directory Server provides advanced LDAP support and tools for writing applications that run on the directory. It also includes improvements to continuous operations and heterogeneous replication between LDAP servers.

Novell Directory Services NDS (Novell Directory Services) is a feature in NetWare 4.X that provides distributed directory services similar to the X.5OO specification. Novell has used NDS on Windows NT and UNIX platforms. A dedicated e-commerce version of NDS is also available.

Microsoft Active Directory Active Directory combines the Internet's DNS location service and X.500 naming capabilities. LDAP is the core access protocol for this service. LDAP enables Microsoft's Active Directory to run across operating system boundaries and integrate multiple namespaces, thus enabling administrators to manage directory services from other vendors. For more information, see "Microsoft Active Directory."

The Directory Interoperability Forum was formed to advance open directories based on the LDAP standard. The forum consists of open catalog vendors who plan to develop standards bodies to accelerate the development and implementation of catalog-based applications.