Users Guide

84| Software Licenses Dell Networking W-Series ArubaOS 6.5.x| User Guide
version licensing feature is not supported in a topology where a single licensing server or a pair of primary and
backup licensing servers are connected to one or more local controllers.
Replacing a Controller
If you need to replace the controller acting as a license server, the keys installed on the previous license server
must be regenerated and added to the new license server. If you need to replace a controller acting as license
client, you must regenerate the license keys installed on the client and reinstall them on the replacement client
or the licensing server.
Failover Behaviors
If the primary licensing server fails, the controller acting as a backup license server will retain the shared license
limits until the backup server reboots. If both the primary and the backup license servers fail, or if the backup
controller reboots before the primary controller comes back up, License clients will retain the license limits sent
to them by the licensing server for 30 days.
Although a client controller retains its licensing information for 30 days after it loses contact with the licensing
server, if the client reboots at any time during this 30-day window, the window will restart, and the client will retain its
information for another 30 days.
APs that use centralized licensing in conjunction with a ArubaOS high availability feature behave differently
than APs that do not use a high availability solution. APs using VRRP redundancy, a backup LMS, or the
ArubaOS fast failover feature can quickly fail over to a backup controller, even if that backup controller does
not have any AP licenses at the time of the failover. However, if that AP reboots, it will not obtain its licenses
until the backup controller receives the required licenses from the licensing master.
Client is Unreachable
The centralized licensing feature sends keepalive heartbeats between the license server and the licensing client
controllers every 30 seconds. If the licensing server fails to receive three consecutive heartbeats from a client, it
assumes that the licensing client is down, and that any APs associated with that client are also down or have
failed over to another controller . Therefore, the licensing server adds any licenses used by that client back into
the available pool of licenses. If the license server fails to contact a license client for 30 consecutive days, any
licenses individually installed on that client will be removed from the server’s license database.
The WebUI of the licensing client and the licensing server both display a warning message when a licensing client
and licensing server are unable to communicate.
Server is Unreachable
If a licensing client does not receive three consecutive heartbeats from the server, it assumes that the server is
down, and that any APs directly associated to the server are also down or have failed over to another
controller. The client then adds any licenses used by the licensing server into to the pool of available licenses on
that client. When a license client is unable to reach a license server for 30 consecutive days, it removes any
shared licenses pushed to it from the licensing server, and reverts to its installed licenses. If the 30-day window
has passed and the controller does not have enough installed licenses for all of its associated APs, the
controller will nonetheless continue to support each AP. However, when an AP reboots and its controller does
not have enough licenses, that AP will not come up.
For more information on replacing a controller using the centralized licensing feature, see Replacing a Controller on
page 44