The Ultimate Guide to Checking Domain Functional Level

Domain functional level (DFL) is a concept in Microsoft Active Directory (AD) that defines the highest level of functionality that a domain can operate at. It determines the features and capabilities that are available within the domain, such as the ability to use certain group policies, Kerberos authentication, and other advanced features. Checking the DFL of a domain is important for ensuring that it is operating at the optimal level for its needs and that all the necessary features are enabled.

There are five DFLs in AD:

Windows 2000
Windows 2003
Windows 2008
Windows 2012
Windows 2016

To check the DFL of a domain, you can use the following steps:

Open the Active Directory Users and Computers console.
Right-click the domain object and select Properties.
Click the General tab.
The DFL will be displayed in the Functional Level field.

It is important to note that raising the DFL of a domain is a one-way operation. Once a domain has been raised to a higher DFL, it cannot be lowered back down to a lower DFL. Therefore, it is important to carefully consider the impact of raising the DFL before doing so.

Table of Contents

1. Identify

Identifying the current DFL of a domain is a crucial step in the process of checking the domain functional level. It allows you to understand the current state of the domain and determine if it is operating at the optimal level for its needs. There are several ways to identify the current DFL of a domain:

Active Directory Users and Computers console: This is the most common method of checking the DFL of a domain. To do this, open the Active Directory Users and Computers console, right-click the domain object, and select Properties. The DFL will be displayed in the Functional Level field on the General tab.
PowerShell: You can also use PowerShell to check the DFL of a domain. To do this, open a PowerShell window and run the following command:
```
Get-ADDomain | Select-Object Name, DomainMode
```
LDAP query: You can also use an LDAP query to check the DFL of a domain. To do this, open an LDAP query tool and run the following query:
```
(&(objectClass=domain)(distinguishedName=DC=example,DC=com))
```

Once you have identified the current DFL of the domain, you can then assess the features and capabilities that are available at that level and determine if they meet the needs of your organization.

2. Assess

Assessing the features and capabilities that are available at the current DFL is a critical step in the process of checking the domain functional level. It allows you to understand the current state of the domain and determine if it is operating at the optimal level for its needs.

To assess the features and capabilities that are available at the current DFL, you should consider the following factors:

The applications and services that are running on the domain.
The security requirements of the organization.
The future plans of the organization, such as any upcoming migrations or upgrades.

Once you have considered these factors, you can then evaluate the features and capabilities that are available at the current DFL to determine if they meet the needs of your organization.

For example, if you are running applications that require a specific feature that is only available at a higher DFL, then you may need to raise the DFL of your domain to support those applications.

3. Plan

Planning for the impact of raising the domain functional level (DFL) to a higher level is a critical component of the process of checking the DFL. This is because raising the DFL can have a significant impact on the domain, including the applications and services that are running on it, the security of the domain, and the future plans of the organization.

To effectively plan for the impact of raising the DFL, it is important to consider the following factors:

The applications and services that are running on the domain.
The security requirements of the organization.
The future plans of the organization, such as any upcoming migrations or upgrades.

Once these factors have been considered, you can then develop a plan to mitigate any potential negative impacts of raising the DFL. For example, if you are running applications that require a specific feature that is only available at a higher DFL, then you may need to upgrade those applications before raising the DFL.

It is also important to note that raising the DFL of a domain is a one-way operation. Once a domain has been raised to a higher DFL, it cannot be lowered back down to a lower DFL. Therefore, it is important to carefully consider the impact of raising the DFL before doing so.

4. Implement

Raising the domain functional level (DFL) of a domain to the desired level is a critical step in the process of checking the DFL. This is because the DFL determines the features and capabilities that are available within the domain, and raising the DFL can allow you to enable new features and capabilities that are not available at lower DFLs. For example, raising the DFL to Windows Server 2012 R2 will allow you to enable features such as Active Directory Recycle Bin and Privileged Access Management.

To raise the DFL of a domain, you can use the Active Directory Domain Services (AD DS) command-line tools. The following command will raise the DFL of the domain named “example.com” to Windows Server 2012 R2:

raisedomainforestlvl /forest:example.com /domain:example.com /level:2012

Once the DFL of the domain has been raised, you will need to reboot all of the domain controllers in the domain.

FAQs on How to Check Domain Functional Level

This section provides answers to frequently asked questions on how to check the domain functional level (DFL) of a domain in Active Directory.

Question 1: What is the domain functional level?

The domain functional level (DFL) determines the highest level of functionality that a domain can operate at. It defines the features and capabilities that are available within the domain, such as the ability to use certain group policies, Kerberos authentication, and other advanced features.

Question 2: Why is it important to check the DFL of a domain?

Checking the DFL of a domain is important for ensuring that the domain is operating at the optimal level for its needs. It also helps to ensure that all the necessary features and capabilities are enabled.

Question 3: How can I check the DFL of a domain?

You can check the DFL of a domain using the Active Directory Users and Computers console. To do this, open the console, right-click the domain object, and select Properties. The DFL will be displayed in the Functional Level field on the General tab.

Question 4: What are the different DFLs that are available?

There are five DFLs that are available in Active Directory:

Windows 2000
Windows 2003
Windows 2008
Windows 2012
Windows 2016

Question 5: How do I raise the DFL of a domain?

To raise the DFL of a domain, you can use the Active Directory Domain Services (AD DS) command-line tools. The command to raise the DFL will vary depending on the target DFL.

Question 6: Is it possible to lower the DFL of a domain?

No, it is not possible to lower the DFL of a domain. Once a domain has been raised to a higher DFL, it cannot be lowered back down to a lower DFL.

Summary: Checking the DFL of a domain is important for ensuring that the domain is operating at the optimal level for its needs and that all the necessary features are enabled. Raising the DFL of a domain can provide access to new features and capabilities, but it is important to carefully consider the impact of raising the DFL before doing so.

Next: Understanding the Different Domain Functional Levels

Tips for Checking the Domain Functional Level

Checking the domain functional level (DFL) of a domain is important for ensuring that the domain is operating at the optimal level for its needs. Here are a few tips to help you check the DFL of a domain:

Tip 1: Use the Active Directory Users and Computers console

The Active Directory Users and Computers console is a graphical tool that can be used to manage Active Directory objects, including domains. To check the DFL of a domain using the console, open the console, right-click the domain object, and select Properties. The DFL will be displayed in the Functional Level field on the General tab.

Tip 2: Use PowerShell

PowerShell is a command-line tool that can be used to manage Active Directory objects, including domains. To check the DFL of a domain using PowerShell, open a PowerShell window and run the following command:Get-ADDomain | Select-Object Name, DomainMode

Tip 3: Use an LDAP query

LDAP (Lightweight Directory Access Protocol) is a protocol that can be used to access Active Directory objects. To check the DFL of a domain using an LDAP query, open an LDAP query tool and run the following query:(&(objectClass=domain)(distinguishedName=DC=example,DC=com))

Tip 4: Consider the impact of raising the DFL

Raising the DFL of a domain can have a significant impact on the domain, including the applications and services that are running on it, the security of the domain, and the future plans of the organization. It is important to carefully consider the impact of raising the DFL before doing so.

Tip 5: Use the Active Directory Domain Services (AD DS) command-line tools to raise the DFL

The AD DS command-line tools can be used to raise the DFL of a domain. The command to raise the DFL will vary depending on the target DFL.

Summary: Checking the DFL of a domain is important for ensuring that the domain is operating at the optimal level for its needs. By following these tips, you can easily check the DFL of a domain and make sure that it is set to the correct level.

Next: Understanding the Different Domain Functional Levels

Concluding Remarks on Checking Domain Functional Level

In conclusion, checking the domain functional level (DFL) of a domain is a critical task for any Active Directory administrator. The DFL determines the features and capabilities that are available within the domain, and it is important to ensure that the DFL is set to the correct level for the domain’s needs.

There are several methods that can be used to check the DFL of a domain, including the Active Directory Users and Computers console, PowerShell, and LDAP queries. It is also important to consider the impact of raising the DFL before doing so, as it can have a significant impact on the domain.

By following the tips and advice provided in this article, you can easily check the DFL of a domain and make sure that it is set to the correct level for its needs. This will help to ensure that the domain is operating at the optimal level for its users and applications.

As Active Directory continues to evolve, it is likely that new DFLs will be introduced in the future. It is important to stay up-to-date on the latest DFLs and their impact on Active Directory.