Access Point Switchover and Migration

Switchover driven by Access Points
In this scenario, there is no direct communication between primary or secondary WLCs. But switchover of traffic is driven by Access Points.
Access Points are manually configured (via Management Console/GUI), with Primary and Secondary WLC information. AP automatically switches to secondary controller if primary is not responding. When Primary WLC goes down, AP stops receiving ‘keep-alive’ request from it.
By recognizing the loss of this request, AP starts sending join request to secondary WLC IP (which is already configured), and establishes the connection. Once primary is up, AP again reverts its connection toward primary WLC IP.
This is simplest failover configuration and the process may cause interruption of wireless service to user.
The WLCs are not HA aware and no heart beat happens between WLCs. However, an AP is always up and running under any one of the WLCs.
Access Point Migration
Spectrum identifies the mobility/migration of one AP from one WLC to another. When you remove an AP from one WLC and connect to another WLC physically, then in Spectrum the AP model under the previous WLC is moved to the WLC you have subsequently connected to. This happens after the next poll interval of the new WLC that the AP has connected to. On successful migration, an AP migration event (
Attribute ID: 0x6760001
) will be raised on that WLC which the AP has now has connected to.
: AP model is not deleted and recreated during migration (unless you explicitly do so), but same existing AP model is updated with its parent WLC relation.
Access Point Migration Purge Interval (hrs)
value is set to 24 (hours), by default.
You can configure the same from
WLC Manager
Component Detail
Information Tab
: If Access Point is removed from one WLC and is not attached or migrated to any other WLC within Purge interval, then AP Migration event is not raised.