Directory Services

Directory

A centralized, hierarchical information repository that organizes and centralizes objects like users, groups, devices, and applications.

Directory Service

Protocols, functions, and APIs that allow access to directory information, such as DAP and LDAP.

Directory Functionality

Provides centralized authentication, enables single sign-on, serves as a network 'phone book', supports granular administration control.

Directory Structure

In a hierarchical tree format with a Root, Branches, and Leaves.

What are the two common ways to arrange a directory?

Geographically or functionally, or a combination of both.

Pruning/Grafting

The ability to move objects (users, groups, computers) within the directory tree.

Directory attributes and inheritance

Objects inherit attributes from their location, ensuring consistency; moving objects changes their inherited attributes.

Directory Schema

Defines the attribute types, structure, container objects, and leaf objects in a directory.

Common Container Objects

Country (c), Organization (o), Organizational Unit (ou), Group of names.

Leaf Object

An object that cannot contain other objects, such as a person, computer, or printer.

Leaf object Attributes

For a printer: Make/model, Duplex capability, Color or B&W, Paper sizes available.

Directory-enabled applications

Applications that rely on the directory for information, such as user login, VPN authentication, and digital signatures.

Organizational Unit (OU)

A container within a directory that can be nested and used to structure objects logically.

Distinguished Name (DN)

A unique identifier for an entry in the directory, which can be absolute or relative.

Directory Naming Layers Conventions

c = Country, o = Organization, ou = Organizational Unit, cn = Common Name.

X.500

The original directory standard developed by ITU-T, introducing tree structures, attributes, DN, and RDN.

Components of X.500

DSA (Directory System Agent), DUA (Directory User Agent), DAP (Directory Access Protocol), DSP (Directory System Protocol).

LDAP

a standardized method for querying and modifying directory services over TCP/IP.

What port does LDAP operate on?

TCP port 389.

Active Directory

Microsoft's directory service based on X.500, replacing NTDS since 2000.

eDirectory

Novell’s directory service (previously NDS), loosely based on X.500.

Open Directory

Apple’s directory service using LDAP and Kerberos, integrating with Active Directory.

When is a directory service required?

Essential for large organizations with multiple locations and departments; not typically required for small businesses with simple IT needs.