Netgear WC7500-Wireless User Manual - Page 297

ProSAFE Wireless Controller Manage a Redundancy Group With N:1 Redundancy The wireless controller supports N:1 redundancy with failover. Redundancy is implemented through the use of the Virtual Router Redundancy Protocol (VRRP). For information about 1:1 redundancy, see Manage Redundancy for a Single Controller on page 291. VRRP N:1 Redundancy Concepts With N:1 redundancy, you can add one redundant controller for up to three controllers, that is, a redundancy group can consist of four controllers, one of which is a redundant controller. The controllers that are served by the redundant controller must function in a stack in which one controller is the master and the other controllers are the slaves. However, in relation to the redundant controller (also referred to as the secondary controller), both the master and the slaves function as primary controllers because the redundant controller can take over for the master or for any of the slaves. In an N:1 redundancy group with three primary controllers and one redundant controller, you could consider the redundant controller to consist of three virtual controllers, each of which maintains a redundancy relationship with a primary controller. You need a unique VRRP ID for each relationship. Each controller in the redundancy group is assigned a unique controller IP address and a unique local IP address. Local addresses remain constant so that a controller can always be identified before and after a failover. If a primary controller fails or is disconnected from the network, an automatic failover to the redundant controller occurs. The redundant controller then takes ownership of the controller IP address of the primary controller and takes over all functions of the primary controller. After a failover occurs, redundancy no longer exists for the other primary controllers in the redundancy group. Manage Stacking and Redundancy 297