Netgear WC7600v1 - ProSAFE Wireless Controller User Manual

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 

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.