This is what the release notes say about upgrading a cluster: "To reduce the number of reconnection attempts due to VIP failover, Pulse Secure recommends to upgrade the passive node first. Once the upgrade is complete, the passive node will push the service package to the active node and cause the VIP to failover to the passive node. All existing user session will be automatically transferred to the passive node. When the active node has completed the upgrade process, the passive node will remain the VIP owner. If you would like the active node to own the VIP again, a manual failover is required. Note: The term “passive node” used in this example to describe the node that does NOT own the VIP." ... View more