--> AP Failover is a method of moving to another wireless controller when access point connected or associated with wireless controller goes down.
--> In order AP Failover to work, we need to inform the list of the wireless controller which it should join in case of connected wireless controller goes down.
--> Access Point learns a list of wireless controllers during discovery process but once it successfully joins to any controller then access point deletes the list of wireless controllers which it got learned via discovery process.
--> This can be done by using three methods ( Priority order)
i) Per Access Point Primary/Secondary/Tertiary Controller ( Fast Heart Beat Timers is Optional)
ii) Global Backup Primary/Secondary Controller
iii) Mobility Group List ( Fast Heart Beat Timers is Optional)
--> In order to verify which controllers access point failovers to use the following command on an access point in Mobility Group.
AP# show capwap client config
--> In order to verify which controllers access point failovers to use the following command on an access point in case of Global Backup Primary/Secondary Controller.
AP# show capwap client ha
--> Access Point uses heartbeats similar to hello messages to find out whether the wireless controller is working or not.
--> By default Access Points send heartbeat for every 30 seconds.
--> If the Access Point does not get the response to the heartbeat from controller then Access Point sends 1 heartbeat a second for 5 seconds if that also goes down then Access Point moves to other Wireless Controller.
--> We can also configure priority to Access Points so that high priority access points can be always joined to the wireless controller whenever there is contention to the wireless controller by using AP Failover Priority.
--> Faster Heartbeats need to be enabled on the wireless controller if we are using Global Backup Primary/Secondary controller method.
--> Access Points continuously try to send primary discovery request message to the primary wireless controller for every 30 seconds so that it can join once primary controller comes back online in the network.
--> AP Fall back should be enabled in order access points to go back to primary controller once primary controller comes back online.
--> AP Fall Back setting is by default enabled.
--> In order AP Failover to work, we need to inform the list of the wireless controller which it should join in case of connected wireless controller goes down.
--> Access Point learns a list of wireless controllers during discovery process but once it successfully joins to any controller then access point deletes the list of wireless controllers which it got learned via discovery process.
--> Access Point remembers only the list of wireless controllers which is configured on the joined controller after discovery process.
--> This can be done by using three methods ( Priority order)
i) Per Access Point Primary/Secondary/Tertiary Controller ( Fast Heart Beat Timers is Optional)
ii) Global Backup Primary/Secondary Controller
iii) Mobility Group List ( Fast Heart Beat Timers is Optional)
--> In order to verify which controllers access point failovers to use the following command on an access point in Mobility Group.
AP# show capwap client config
--> In order to verify which controllers access point failovers to use the following command on an access point in case of Global Backup Primary/Secondary Controller.
AP# show capwap client ha
--> Access Point uses heartbeats similar to hello messages to find out whether the wireless controller is working or not.
--> By default Access Points send heartbeat for every 30 seconds.
--> If the Access Point does not get the response to the heartbeat from controller then Access Point sends 1 heartbeat a second for 5 seconds if that also goes down then Access Point moves to other Wireless Controller.
--> We can also configure priority to Access Points so that high priority access points can be always joined to the wireless controller whenever there is contention to the wireless controller by using AP Failover Priority.
--> Faster Heartbeats need to be enabled on the wireless controller if we are using Global Backup Primary/Secondary controller method.
--> Access Points continuously try to send primary discovery request message to the primary wireless controller for every 30 seconds so that it can join once primary controller comes back online in the network.
--> AP Fall back should be enabled in order access points to go back to primary controller once primary controller comes back online.
--> AP Fall Back setting is by default enabled.
Very useful, I just was looking for this. A couple of questions:
ReplyDelete- What's the purpose of backup controller? I mean, I can use second and third controlller. Why I should I need two backup controllers?
- Talking about licenses. For example in a 30 AP network, should I need 30 license count in both controllers?
Regards.