Session failover
FortiGate-7000E session synchronization involves the primary FortiGate-7000E informing the secondary FortiGate-7000E of changes to the primary FortiGate-7000E connection and state tables, keeping the secondary FortiGate-7000E up-to-date with the traffic currently being processed by the cluster.
After an HA failover, because of session synchronization the new primary FortiGate-7000E recognizes open sessions that were being handled by the cluster. The sessions continue to be processed by the new primary FortiGate-7000E and are handled according to their last known state.