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What is Active Directory and How to Use AD Effectively

  author
Published By Mohit Jha
Nimisha Ramesh
Approved By Nimisha Ramesh
Published On December 13th, 2023
Reading Time 7 Minutes Reading

The answer to what is Active Directory is quite simple. Active Directory is a combination of a storage and service portfolio. 

This means that AD is Microsoft’s version of a dynamically managed storage that combines various services under a single umbrella. 

It links users with the resources present on the network and provides a secure platform for work. 

The “Active” part in its name signifies its ability to adjust according to the user’s demand. Whereas by “Directory” Microsoft wants to highlight how easily it holds all the information.

The two key parameters that form the cornerstone of the Active Directory are “Assisting Authenticity” and “Allowing Authority”. 

By providing inbuilt provisions for verifying passwords and user IDs it acts as a gatekeeper to the organizational data. 

While privileged access to known entities maintains the need-to-know condition on the various resources. With this introduction, we are in the best position to know about how Active Directory came to be. Let’s dive in.

History and Evolution of Active Directory as a Modern Service

We have a basic idea of what is Active Directory which will help us understand its origin. Although AD is now synonymous with Windows servers it was not in its early days. Before AD, there was NTDS. Introduced as a companion directory service for Windows NT 3.1. Even when limited to basic storage and fetch operations NTDS showed promise. Proven by the fact that it was used to such a degree that admins even put their custom solutions to enhance its capabilities. 

So Microsoft listened to its customers and made AD a permanent part of future Windows Server versions. On its debut with Windows 2000, AD got multiple new services like multi-domain forests, organizational units (OUs), Group Policy, and Active Directory Certificate Services (ADCS). Not only this but security also went up a notch with features like Kerberos authentication and domain isolation.

After this, Microsoft never looked back. Every new update on Windows Server, Active Directory got some enhancements as well. 

2003: AD was optimized for large network handling plus it was directly integrated with other Microsoft services such as Exchange Server and SharePoint Server. Increasing its effectiveness to new heights.

2008:  Was marked with the introduction of Active Directory Lightweight Directory Services (AD LDS) and Active Directory Domain Services for Small Business Server (AD DS SBS).

The security apparatus was revamped and Windows Defender Advanced Threat Protection (ATP) and Credential Guard were added.

2022: Active Directory now has cloud integration. 

What Makes an Active Directory “Active”

There are a few key aspects that allow the word “Active” to fit in perfectly with the Active Directory. Let’s discuss them one by one.
Dynamic Updates: Active Directory removes the need for manual updation entirely. It makes admins free from this mundane task which is a major upgrade from static traditional directories. 

This dynamic nature is not limited to updates only. Any structural changes like the addition/removal of resources are replicated across all instances in real-time.

Auto Monitoring: There exists a dedicated dashboard containing the complete information of the Active Directory. With this admins get a centralized and consistent view of the entire AD at once. This again signifies how Active Directory allows admins to actively monitor their organizations.

What is in the “Directory” of an Active Directory?

We can’t complete our answer on what is Active Directory without discussing its underlying structure. 

AD has both horizontal and vertical separation between different components.

It is divided into >> Forests that split into >> Trees which further contain individual >> Domains 

Domains in itself have one or more Organizational Units. These are a set of computers,  users, printers, files, and other resources. 

OUs can contain other OUs as long as organizational policies allow them. 

Let’s take an example of Company A. It is a medium-scale electronics business selling its product nationwide. Company A also operates a subsidiary B that takes care of all marketing and sales-related tasks. 

So when the IT admin of A sets up an Active Directory they create two forests A and B

Within those Forests, each department like HR, Diagnostics, and Quality has its own Trees. 

Inside the trees there exist several domains for different teams each having a complete set of users, computers, etc. Like wise a similar structure exists for the forest of B as well.

How and When to Use AD

AD is part of your Windows Server so it works on the principle of delegation. Delegation or control can be assigned at the OU level( and is recommended too) once assigned each OU can act independently on matters of adding, or removing resources. 

This delegation work is part of the Active Directory Domain Services of the AD. Moreover, it is managed by specialized servers called Domain Controllers. However, while selecting a server, administrators must make sure that they don’t cause interference with the currently existing service. Otherwise, issues like “exchange database mounting can popup”.

They are responsible for:

Authenticating users: Verifying their identity and granting access to resources. The process (from the user’s point of view) goes like this :

  • Enter the username and password on your computer.
  • Your computer sends a request to the server (DC).
  • The server checks if your login details are correct.
  • If everything is okay, you get access to what you need (with prior permission).

Authorizing access: Determining what actions users can perform on resources.

Replicating data: Keeping all DCs synchronized with the latest information. It operates on a multi-master replication.

Among the DC there is yet another specialized server called the Global Catalog server (GCS). Its job is to store all changes made on not only the domain under its control but also maintain a copy of all changes happening on other DCs. Once the source DC completes its set of changes the GCS broadcasts this information to all other Domain Controllers. All management-related tasks can be completed at the OU level

Whereas policies involving security are directly applied at the forest level. So all Trees and subsequently the underlying domains automatically get updated to the latest security patch. 

Interdomain communication is allowed by default as long as the two endpoints are in the same forest. However, inter-forest communication is strictly forbidden. The only way to breach this boundary is when the global admin establishes a trust relation between both forests. 

What’s Next for Active Directory

Now that we know what is Active Directory it is the right time to discuss what the future holds for this technology. There are many questions in the mind of admins starting from whether is it necessary to invest in such a mechanism. For every such question, the answer varies. Like if you are a small business owner you might not require severeal diffrent domains. So, using Active Driectory can help you to consolidate the data at a single management point. Likewise many different scenarios exist. However, one thing is for sure AD is going to remain an essential tool for the foreseeable future. With the introduction of AI as a feature in AD Microsoft has given the signal that AD is not going anywhere. 

After Learning What is Active Directory Users also Ask These Questions

Q. What is the long-term prediction for AD? 

Ans. AD has been part of many organizations for decades, and it has only gained prestige in all these years. With continuous support and ever-increasing usage statistics, we are confident to say that AD is here to stay. 

Q. Where does it lie on the list of priorities for an organization?

Ans. Any organization that prioritizes AD integration in its workflow is bound to witness tremendous productivity growth. No other product in the market provides such excellent integration with so many top-of-the-line products all under a single ecosystem.

Q. When should I start using an Active Directory?

Ans. As soon as you can, delaying AD usage is costing you in real time. Admins should plan with their team and begin an AD integration right away.

Q. Why does Active Directory have such a name?

Ans. It is Active (Available Anytime) + Directory (Storage Service).

Q. How does an AD work?

Ans. When Domain Controller validates a user request it allows them access to the resources.