Multi-Version Cluster (MVC) Upgrade
The Multi-Version Cluster Two or more Security Gateways that work together in a redundant configuration - High Availability, or Load Sharing. (MVC) mechanism synchronizes connections between Cluster Members that run different versions.
You can upgrade to a newer version without a loss in connectivity (Zero Downtime Upgrade) and test the new version on some of the Cluster Members before you decide to upgrade the rest of the Cluster Members.