Removing WLCs from list in NVRAM for deployed LAPs

Unanswered Question
Feb 25th, 2009


Here is a question, which I really would like to have an answer on. I have been searching for this, and can not find any on this. I am up to the point where I start to think it is simply not possible.

I would like to remove all existing WLCs from NVRAM in my LAPs. Simple, you may think, just boot it without registering and perform the command "clear lwapp private-config", and allthough this is through and I'm sure it will work, it would require me to organize about 300 LAPs to be shipped back to me so I can console into it and perform the command.

Another thing I thought of was clearing the config from WCS, but I found this only clears the config and not the list of previously joined controllers stored in NVRAM.

The background of my request is that we started out with WLCs back in code 3.1, and there it was recommended to have one mobility group if you wanted to have an anchor guest controller.

Today, we are running 5.2 and the number of WLCs we have in place is 21 and growing.

I believe that since we went to 4.2 we started having problems with LAPs sometimes registering to the wrong controller.

We have been troubelshooting this a lot, and with the current discoverey mechanism, where the LWAPP discovery respons includes all controllers in the mobility group, and aso the previously joined/learned controlelrs, we do understand why it happens.

So, the new updated design is to separate into different mobility groups and still make the necessary relationships to the guest anchor controller in the old mobility group. Works all fine. However, it did not resolve the problem of LAPs sometimes registering to the wrong controller.

And it makes sense if you read the documents, the LAP has learned and stored about all the WLCs in NVRAM, so it can select any, if for some reason the primary fails (it only happens ofcourse when the primary fails).

So, to ensure it will no longer rehome to another controller, I do need to remove all previuosly learned WLCs from NVRAM, but can not seem to find a way to do this without having console access, and I have about 300 LAPs in different countries, over appr. 30 locations.....


Thanks in advance for your thoughts on this,


I have this problem too.
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Leo Laohoo Wed, 02/25/2009 - 19:15

Have you tried the "Clear All Configs" option? I'm am avid user of the "clear lwapp private-config" and I've noticed that on the v5.2 firmware, the "Clear All Configs" actually works as well.

Hope this works.

Leo Laohoo Wed, 02/25/2009 - 20:11

Using CLI, you can also use the command "clear ap-config ap_name".

l.mourits Wed, 04/01/2009 - 01:21


Are you convinced this removes stored information in NVRAM for previously joined controllers. So far, my understanding was that only a factry default reset would do so, not the clear all config.

I do understand the clear all config does remove entries for primary, secondary and tertiary controllers but I'm still in doubt if that would ensure the AP will not wander to previously joined controllers.

Kind regards,


Leo Laohoo Wed, 04/01/2009 - 14:40

Hi Leo,

That's what I initially thought. But I was able to test the "clear lwapp private-config" on my desk even when the WLC was located on the same subnet as the AP.

During the Discovery stage, the LAP took a longer time to Join when this command was invoked (and the AP was reloaded/rebooted).

Leo Laohoo Wed, 04/01/2009 - 16:40

Hi Leo,

I know the "clear lwap private-config" works as long as I also include the "clear lwapp ap controller ip address".


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