The accessible features in the domain and the Windows Server version you can use on domain controllers are determined by the functional level of the Active Directory domain and forest.
You won’t be able to use the Active Directory Recycle Bin if you have Windows Server 2016 domain controllers and the domain functional level is only Windows Server 2003. (introduced in the AD version in Windows Server 2008 R2). We’ll teach you how to upgrade the functional level of your Active Directory domain and forest from Windows Server 2012 R2 to Windows Server 2016.
How to Check the Domain and Forest Functional Levels?
The Active Directory Domains and Trusts mmc snap-in can be used to determine the current domain and forest functional level (domain.msc). Open the properties of your domain. On the General page, you’ll find a list of domain and forest functional levels. This is Windows Server 2012 R2 in our situation.
Using PowerShell, you can see the current domain functional level:
Get-ADDomain | fl Name, DomainModeWindows2012R2Domain
Now let’s check the forest functional level:
Get-ADForest | fl Name, ForestModeWindows2012R2Forest
How to Raise Active Directory Domain and Forest Functional Levels?
You must upgrade the Windows Server version on all domain controllers to Windows Server 2016 before you may raise the domain and forest functional level. With Windows Server 2016, you can upgrade in-place (not recommended), deploy additional domain controllers, and properly delete legacy DC versions from your Active Directory environment.
The password for the krbtgt account will be forcibly reset when you upgrade the domain functional level from Windows Server 2003 to a newer version. This may have an impact on Exchange service availability. Also, remember to switch the domain’s AD replication from FRS to Distributed File Service (DFS).
You can use the mmc snap-in Active Directory Domains and Trusts to raise a domain’s functional level. Raise Domain Functional Level by right-clicking on the domain name.
In the window that opens, select the functional level Windows Server 2016, and click the Raise button.
All domains in the forest must be updated to the same or higher domain functional level before the forest can be upgraded. You must be a member of the Enterprise Admins group to raise a forest’s functional level. The Active Directory Domains and Trusts snap-in can also be utilized to increase the forest’s functional level.
Raise Forest Functional Level by right-clicking on the snap-root. in’s
Select the desired functional forest level in the following window, then click the Raise button.
Important! The functional level upgrade for the domain and AD forest cannot be undone.
PowerShell can also be used to boost the domain functional level. The command is as follows:
Set-ADDomainMode -identity solutionviews.com -DomainMode Windows2016ForestWait for AD replication to finish, then double-check that all domain controllers are reporting Windows2016Domain as the domain functional level.
Another command is used to raise the forest’s functional level:
Set-ADForestMode -Identity solutionviews.com -ForestMode Windows2016Forest