Technical data

N+1 Redundancy
© 2012 Meru Networks, Inc. Implementing Redundancy 105
Recovering From N+1 Failover
When an N+1 master controller goes down, the slave controller transitions from
passive slave to active slave (failover) and starts acting as the master controller.
When the original master comes back up, the active slave becomes the passive slave
again (fallback). The APs then reboot and discover the master controller again.
Recovering From N+1 with Dual Ethernet Failover
On the Master controller, when the first Ethernet interface goes down, the controller
fails over to second interface of the same controller. If the second interface goes
down, Nplus1 failover takes place and the N+1 passive slave becomes an active slave
with Dual Ethernet redundant configuration.
For MC: master_ip State: SW
Mismatch -> No Access -
Saved Config does not exist
Software mismatch was resolved, but the Master
Controller is not accessible from the Slave Controller
and cannot provide redundancy. Ensure that the Master
Controller is accessible using the command nplus1
access master_ip.
For MC: master_ip State:
WTR Set-> WTR - Copyback
Done
Failback process has begun, WTR timer initiated and is
in the process of counting down, and the Master
Controller is accessible. The failback process cannot
complete and the Master Controller cannot provide
redundancy until WTR expires.
For MC: master_ip State:
WTR Set-> WTR - No Access
Failback process has begun, WTR timer initiated and is
in the process of counting down, but the Master
Controller is not accessible. Ensure that the Master
Controller is accessible, and verify by using the
command nplus1 access master_ip.
Could not access host:
master_ip. Setting No Access
Count to: count
Could not access the Master Controller. The Master
Controller cannot provide redundancy until it is
accessible. Access will be rechecked after count
(default is 60 seconds). The problem may be caused by
a gateway failure. Ensure that the Master Controller is
accessible, and verify by using the command nplus1
access master_ip.
Note:
If non-revertive mode is enabled, the Active to Passive Slave transition
does not take place until revert is executed at its scheduled time/date
or it should be executed forcibly. During this scenario, the standby
master takes over the master role. The APs drop the Active slave and
discovers the original master controller again.