WLC redundancy and wireless clients behaviour

bobut · ‎03-22-2010

Can I create WLC redundancy between 2 types of controller running the same software version ? For example WLC5508 and a WLC2106

We should presume that we are running the lates Sw version 6.x.

If the Primary WLC fails (the AP will have a statical configuration of the Primary/Secondary WLC) what will the AP do ?

Will it reboot and re-associate to the Secondary WLC?

How long it will take to reboot and re-associate?

Will the wireless clients disconnect ?

In order to obtain again wireless network connectivity will the clients required to:

re-associate,

re-login

re-authenticate

to the Secondary Controller?

What about the Guest clients Authenticated through the Lobby Ambassador?

If the Primary WLC comes online will the AP fall back automatic to it? How long it will take to reestablis wireless services.

dancampb · ‎03-22-2010

Yes, you can have redundancy between two different models of controllers. If the primary fails the AP will then join the secondary controller if configured. If you don't have one configured the AP will try to join another controller in the mobility group. During this time when its joining another controller the AP will not be servicing clients, so those connections will be dropped. After it joins the secondary controller they will be operational again and clients and associate again.

The AP sends out primary discovery requests to the address of the configured primary. When it sees its primary is back online it will rejoin the primary controller. Again service will be disrupted during this time. As long as you keep the code versions between the controller the same the join time is pretty short. Longer outages occur when the code versions are different because then the AP has to download code when it joins.