Controller Based WLANs

Question: How the Redundancy and failover mechanism works in Centralized licensing feature ?

- If the license server goes down, the standby license server will take over as the license server. It will continue to send license information to the license clients.

- If the license server goes down and there is no standby license server, no license limits can be sent to client controllers that are starting up while the license server is down.

- Existing controllers that had license limits sent to them will continue to function as normal for 30 days. If the license client reboots before the 30 days are up, it will retain the license limits received from the server for another 30 days.

- When the license server is unable to reach a license client for 30 days, the licenses that were imported from it will be removed from the license database. This is to prevent abuse of the centralized license mechanism.

- If an AP fails over from one client controller to another, the AP will be allowed to come up even if there are not sufficient licenses present. This is to ensure that redundancy is not broken. However, if the AP reboots after failing over it will only be allowed to come up if sufficient licenses are present.

- If the license server has not received 3 consecutive heartbeats (3*30=90secs) from a client, it will add the clients used license limits to the total available limits.

- If the client has not received 3 consecutive heartbeats from the server, it will add the servers used license limits to its own available limits.  This is to ensure that the licenses are redistributed in case of a fail over.