1. Active Directory: Final Solution to Enterprise System Integration
Author: Liming Liao
Date: 2/23/2001

2. What is Directory Services
It is the central authority that manages the identities and brokers the relationships between the distributed resources, enabling them to work together.
Examples: Yellow Pages, Shopping List
It is composed of objects like people, printers, servers, etc.

3. Functions of Directory Service
A place to store information about network-based entities.
A consistent way to name, describe, locate, access, manage, and secure information about these individual resources.

4. Why Directory Service is needed
local area networks (LANs) and wide area networks (WANs) grow larger and more complex.
networks are connected to the Internet.
applications require more from the network and are linked to other systems through corporate intranets.

5. Life without a Central Directory Service

6. Life without a Central Directory Service

7. Disadvantages of life without a Central Directory Service
Data duplicates prone to user errors
same data for one object has to be input several times enterprise-widely
Update information for a single object may require changes to be made to numerous places
Multiple logins for a single user trying to access different databases or networks
Each database in the enterprise requires a separate login name and password
Each network in the enterprise requires a separate login name and password

8. With Centralized Directory Services

9. With Centralized Directory Services

10. Advantages of Directory Services
Entry and management of personal data, such as name, phone number and supervisor, is centralized
These information is entered and stored in one place. If some of the information is entered wrongly or needs to be changed, it is easy to fix
No pain for duplicate inputs and updates

11. Advantages of Directory Services
Information on user ID and password locations for computer systems is centralized
Instead of having user IDS and passwords scattered over several systems, they are managed form the central directory service
Security is improved because there are much less userIDs and passwords
Management of users’ userIDs is much easier for system admins

12. Advantages of Directory Services
The procedure for determining the status and role of an individual in the organization is standardized
In a large organization, there will be a number of people that will come and go. It is important to determine the exact status or relationship to the company they represent

13. Advantages of Directory Services
Lookup of names, addresses, phone numbers and other “white pages” information is standardized
Lookup of network resources like printers, servers, certificates and other “ yellow pages” information is standardized
Centralizing the management of the system will increase reliability and make it easier to keep it up to date

14. Open Directory Service Solutions-
Vendor-specific Directory Service Solution and Open Standards Directory Service Solutions
Directory Services-
Sun Microsystems NIS+ (Network Information Service Plus)
Novell’s NDC (NetWare Directory Service)
Microsoft’s Active Directory
Open Directory Service Solutions-
An Open Solution: X.500
An Open Gateway Service
LDAP - the Lightweighted Directory Access Protocal

15. Microsoft Active Directory
Active Directory is the first enterprise-class directory service that is scaleable, built from the ground up using Internet-standard technologies, and fully integrated with the operating system.

16. Characteristics of Active Directory
Hierarchical Organization
It uses objects to represent network resources.
It uses containers to represent organizations.
It organizes information in a tree structure made up of these objects and containers.
Object-oriented Storage
Different objects can be assigned different attributes.
Administrators can assign access privileges to objects
Multi-Master Replication
Directories can be replicated on different servers and can be maintained locally across the network
User can locate resources using the local directory service rather than contact the central domain controller every time as in NT 4.0.

17. Hierarchical Organization

18. Object-oriented Storage

19. Important ADS concepts
Workgroup
A Windows 2000 workgroup is a logical grouping of networked computers that share resources, such as files and printers, and maintain a local security database, which is a list of user accounts and resource security information for the computer it is on.
Domain
A Windows 2000 domain is a logical grouping of networked computers that share a central directory database, which contains user accounts and security information for the domain.

20. Important ADS concepts
Domain Tree and Forest
A domain tree refers to a hierarchical grouping of domains that share a contiguous namespace, a common schema, and a common global catalog.
A domain forest is a collection of two or more domain trees that do not share a contiguous namespace, but do share common schema and global catalog.
Namespace
A collection of unique domain names.

21. Important ADS concepts
Object and Organizational unit
An object is a representation of a network resource, including users, computers, printers, and so forth.
Organizational unit is an object that can hold other objects.
Multimaster replication
The process by which Active Directory domains replicate with each other and resolve conflicting updates.
Lightweight Directory Access Protocol (LDAP)
An Internet standard by which Active Directory clients and servers communicate.

22. Benefits of Active Directory Service
Simplifies management-
Administrators have a single point of management for user accounts, clients, servers and applications
Administrators can delegate specific administrative privileges and tasks to individual users and groups to make better use of system administration resources
Strengthens security
It supports a number of authentication mechanisms used to prove identity upon logon to Windows 2000
It support a fully integrated public key infrastructure and Internet secure protocols to let organizations securely extend selected directory information beyond their firewall to Extranet users and e-commerce customers

23. Benefits of Active Directory Service
Extends interoperatbility
Expose all of the Windows 2000 directory features through standards-based interfaces.
It provides a development platform for directory-enabled applications.
More efficient usage of resources
Centralized security control and shared logon information saves the trouble of creating security-admin functions of each specific system
Users are exempted of the headache of maintaining multiple security information within a single domain

24. How to implement ADS LDAP ???
Multi-Platform (Unix, Windows NT, OS2 and IBM mainframes)
Multi-Vendor support (Microsoft, Netscape, Sun and Novell)
Common standard
Centralizes the entry and management of personal data like name, phone number, and supervisor
Centralizes the location of user ID and passwords for computer systems
Provides the Simple Authentication and Security Layer(SASL) providers, and the Secure Socket Layer(SSL) Protocol
Centralizes the procedure for determining the status and role of an individual in the organization
Centralizes the lookup of names, addresses, phone numbers and other ‘white page’ information

25. Summary
Directory Services are essential to daily life in a networked world
Personal information that is needed for the running of any organization is being kept in many separate systems
Centralized directory services can improve productivity and increase security while reducing management overhead