03 - AD - Forest, Tree, Domain

Active Directory - Forest, Tree, Domain

Knowledge Base Questions & Answers

What is Forest in AD, and how does it manage domain relationships?

A Forest is a logical structure in AD (Active Directory) that consists of one or more domain trees.
In a Forest, all domains are interconnected by transitive two-way trust relationships, allowing users in any domain to access resources in other domains within the Forest.

What is the “Forest Root Domain” in an AD (Active Directory) Forest, and what is its role and significance?

The first Domain, which is installed on the network and not in any existing forests, is called the “Forest Root Domain.”
It is responsible for managing the overall configuration and settings of the AD Forest.
The “Forest Root Domain” controls the Forest-wide policies, schema, and trust relationships with external Domains or Forests.
It cannot be removed from the Forest without removing the entire Forest itself.
No other Domains can be created above the “Forest Root Domain” in the Forest-Domain hierarchy.

What is a Tree in AD, and how is it created and structured within a Forest?

A Tree is a collection of one or more Domains in a contiguous namespace.
It is formed when a new Domain is added as a “Child Domain” to an existing Domain.
Domains within a Tree share a common configuration, and GC (Global Catalog).
Multiple Trees within a Forest can provide a way to separate different parts of an organization logically or to accommodate separate business units or geographic locations.

What is a Domain in AD?

The Domain is a network collection of users, groups, computers, printers, etc. These objects share a common AD database and security policies.

What is an “Empty Root Domain” in AD, and in what scenarios is it beneficial?

An “Empty Root Domain” is an architectural component in AD design that benefits organizations with decentralized IT (Information Technology) authority, such as universities.
It serves as a placeholder at the root of the AD structure and typically does not contain any users or resources that are not necessary.

What is a “Child Domain” in AD, and how is it related to the "Parent Domain"?

When a new Domain is installed and added to an existing Tree, it is called a “Child Domain.”
The name of a “Child Domain” is appended to the "Parent Domain" name.
“Child Domains” inherit GPOs, security policies and trust relationships from the “Parent Domain”.
They can also have their own "Child Domains".

What does “Functional Level” mean in AD, and how does it impact the system's capabilities and compatibility?

“Functional Level” in AD specifies the features and capabilities available based on the Windows server versions used in the Domain or Forest.
Although low functional levels help to coexist with legacy AD, they will deactivate some of the new features of AD.
“Functional Level” conversion can be reversed.

Experience-Based/Practical Questions & Answers

Is it possible to have multiple Forests in AD, and if so, why would this be done?

Yes, it is possible. Each Forest operates as a separate instance of AD with its own Domain structure and settings.
Multiple Forests are used to keep different organizations or environments separate and independent from each other.

What are the benefits of multiple Forests?

What are the drawbacks of multiple Forests?

Administrative complexity.
Increased infrastructure and costs.
Schema changes and application compatibility. If applications require schema changes, modifying the schema in each forest can be time-consuming and error-prone.
Increased complexity for user management and collaboration.

Can multiple Trees exist within a single AD Forest, and how are they structured?

Yes, it is possible. Each Tree in the Forest represents a separate namespace with its own Domain hierarchy.

How are Domains structured within an AD Forest, and what is the role of the Root and Child domains?

Domains within an AD forest are organized in a hierarchical structure. The “Forest Root Domain” is at the top, followed by "Child Domains."
Each Domain, except the “Forest Root Domain,” has a "Parent Domain."
This hierarchy allows for centralized administration and the establishment trust relationships between Domains.

What are the reasons for implementing multiple Domains in an AD environment?
There are the following purposes for implementing multiple Domains:

What are the drawbacks of using multiple Domains?

How do you check the “Forest Functional Level” on the GUI (Graphic User Interface) console and PowerShell?

Use “Active Directory Domain and Trusts” MMC (Microsoft Management Console) snap-in.

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How do you check the “Domain Functional Level” on the GUI console and PowerShell?

Use “Active Directory Users and Computers” MMC snap-in to check the “Domain Functional Level.”

How can the “Forest Functional Level” be raised in the GUI console?

You can raise the “Forest Functional Level” using the "Active Directory Domains and Trusts" MMC snap-in.

How do you raise the “Domain Functional Level” in the GUI console?

You can raise the “Domain Functional Level” using the "Active Directory Users and Computers" MMC snap-in.

Is it possible to rename a Domain name in AD?

Yes. You can rename the Domain name even without making it down.

What are the differences between a Workgroup and a Domain?

Workgroup:
- A Workgroup is a peer-to-peer network where multiple systems are interconnected to share resources such as files and printers.
- Each system in a Workgroup maintains its own local database for User accounts, security settings, and other configurations.
Domain:
- A Domain is a centralized network infrastructure where multiple systems (clients and servers) are connected to a dedicated server known as a DC (Domain Controller).
- User accounts, security policies, and other configurations are stored in a centralized database called AD, which the DC manages.
- Users have a single Domain account and can log on to any system within the Domain using their Domain credentials.