Software requirements are also important for the correct functioning of a failover cluster:

• Active Directory (AD) domain controllers must be on Windows Server 2008 or later
• Domain and forest functional levels must be on Windows Server 2008 or later
• The DNS server must be on Windows Server 2008 or later
• The application that is planned for high availability should support Windows Server 2016
• Each node should run the same edition of Windows Server 2016
• Each node must have the failover clustering role installed

Once you meet all requirements, you can start implementing a failover cluster.