Wireless Access

Hi all - 

I followed the suggestion in this post where it was suggested to put the campus ap's in bridge mode and tell it to go to remote ap, but I'm having issues with that.

Firstly, is there a better way to have the access points fail over to autonomous mode if the controller goes down? Our controller suddenly stopped working a couple days ago, and now that we've got a replacement we want to make sure that if this happens again we'll still be up and running. Luckily we only had a few users at the time so we were able to re-deploy our old MSM ap's, but if this had happened during peak season we would have been in serious trouble.

The issue we're seeing when putting the ap's into bridge mode is that they no longer pass client traffic. As far as I can tell I have the default gateway pushed out to them, and we use an external DHCP server, so in theory it should all just work (minus all the cool things the controller lets us do, like RF management).

Am I just hoping for something that isn't possible in an environment with a controller?

The classic and proper protection for a controller failure is to have a backup controller installed in your system.  The cost of hardware has come down and the elimination of the cost of backup licensing through centralized licensing make physical controller redundancy attractive.  With physical controller redundancy, it is possible that your users will not even know that there is a failure.

Now, onto your question:

For APs to be able to work without a controller, they must:

- Be configured as remote APS already

- Be serving an SSID that has a preshared key

- That SSID must be using bridge mode

To use bridge mode, the VLANs necessary for users must be trunked to each AP so that it will work when the controller is in and out of the picture.  In this mode, no traffic goes through the controller; it only goes through the APS.  This strategy was very popular before Instant APS, which do not require a controller,  were created.

If you had to build a redundant network network today, I would suggest either Instant APS (which do not require a controller) or a backup controller along with a master controller.