Two identical appliances on the same subnet can be combined as a high-availability pair. The appliances each monitor the other’s status by using the standard Virtual Router Redundancy Protocol (VRRP) heartbeat mechanism. The pair has a common virtual IP address for management, in addition to each appliance’s management IP address. If the primary appliance fails, the secondary appliance takes over. Failover takes approximately five seconds. High availability mode is a standard feature.