Explanation/Reference:
Explanation:
In addition to the pre-requisites of Single-domain clusters, there are additional pre-requisites for Multi- domain or Workgroup clusters in the Windows Server 2016 including Primary DNS Suffix Requirements.
* Each cluster node needs to have a primary DNS suffix.
* For Multi-domain Clusters: The DNS suffix for all the domains in the cluster, should be present on all cluster nodes...
Note: Failover Clusters can now be created in the following configurations:
Single-domain Clusters: Clusters with all nodes joined to the same domain

Multi-domain Clusters: Clusters with nodes which are members of different domains

Workgroup Clusters: Clusters with nodes which are member servers / workgroup (not domain joined)

References: https://blogs.msdn.microsoft.com/clustering/2015/08/17/workgroup-and-multi-domain-clusters- in-windows-server-2016/