What is the highest functional level that can be configured after upgrading all domain controllers to Windows Server 2022?

The highest functional level that can be configured after upgrading all domain controllers to Windows Server 2022 is Windows Server 2022. Each server operating system version introduces new features and improvements in Active Directory and other services. By upgrading all domain controllers to the latest version, you can take advantage of the functionalities and security updates introduced with Windows Server 2022.

Maintaining the highest functional level ensures that all features provided by the newest version are accessible and operational, which enhances the overall performance and security of your environment. Choosing any earlier functional levels like Windows Server 2019, 2016, or 2012 would limit the ability to utilize the advancements made in Windows Server 2022, thereby hindering efficiency and potentially impacting security protocols available only at the highest functional level.