Date: March 13, 2018
SQL Server Management Studio In A Multi-Site Cluster
When setting up a multisite cluster (nodes in different subnets), you will find that by default the cluster enables RegisterAllProvidersIP cluster resource for its network name. This results in two entries in DNS for the SQL Cluster name resource. One for each cluster IP address. If you use the optional MultiSubnetFailover=True parameter in the connection string, clients will try both IP addresses simultaneously. Following which, it would connect to the first server that responds. For SQL Server Management Studio, add that setting under the additional Connections Parameters.
Reproduced with permission from https://clusteringformeremortals.com/2015/03/24/sql-server-management-studio-in-a-multi-site-cluster/