The Extreme Networks ExtremeWireless solution provides availability against AP outages, controller outages, and even network outages. The controller in a VLAN bridged topology can potentially allow the user to retain the IP address in a failover scenario, if the VNS/VLAN is common to both controllers. For example, availability is provided by defining a paired controller configuration by which each peer can act as the backup controller for the other's APs. APs in one controller are allowed to fail over and register with the alternate controller.
If the primary controller fails, all of its associated APs can automatically switch over to another controller that has been defined as the secondary or backup controller. If an AP reboots, the primary controller is restored if it is active. However, active APs will continue to be connected to the backup controller until the administrator releases them back to the primary home controller.