Specifications

BPG_11n_v1.0 | Page 19
Whether active-active or active-standby is deployed it is advisable to have the controller
Ethernet ports connected to separate Ethernet switches (excluding the case where port
bonding is used). Having the controller uplink ports “homed” to separate switches adds a
level of wired network redundancy.
Redundant Controllers Deployments
N+1
Controller redundancy is accomplished by the N+1 model where we have a standby
controller that is a backup for all of the controllers in a cluster. The maximum number of
controllers supported per cluster is 5. All controllers in the cluster (master/s and slave) need
to be the same model. N+1 is a licensed feature. (If N = 1, an N+1 license is not required.)
In the N+1 redundancy model the slave controller can assume configuration state of any one
master controller at a time, where N can be 1-5 production controllers. The slave controller
assumes the IP address and last saved configuration of the master controller for which health
advertisements have not been received within a specified interval..
The following image is an illustration of an N+1 setup where N=5.
All controllers must be the same model number and be running the release of System
Director. All controllers must be on same L2 subnet.
The use of static IP is always recommended for controller IP addresses and for N+1 it is
mandatory. Be sure to have sufficient AP licenses on the slave controller for failed-over APs.
All APs must be configured to connect as L3 preferred when N>1. Spanning tree should
disabled on controller switch ports. The controller switch uplink port for the slave controller
must be configured to support all of the VLANs configured on the any of the controllers in the
cluster.
MERU BEST PRACTICES GUIDE | 11n Design, Implementation and Optimization