Multi-Subnet Clustering

multi-subnet clustering

A SQL Server multi-subnet failover cluster is a configuration in which each failover cluster node

is connected to a different subnet or a different set of subnets. These subnets can be in the

same location or in geographically dispersed sites. Clusters in geographically dispersed sites

are sometimes referred to as

stretch clusters. Because there’s no shared storage that all the

nodes can access, data should be replicated between the data storage on the multiple subnets.

When you replicate data, there’s more than one copy of the data available. Therefore, a multi-

subnet failover cluster provides a disaster recovery solution in addition to high availability.

The following illustration represents a two-node, two-subnet failover cluster instance (FCI) in.

Following are some examples of SQL Server FCIs that use multiple subnets:

multi-subnet failover cluster (two