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New Member

Upgrading WLC's

Will the ap's be affected if you are upgrading a controller?

I am would like to upgrade my anchor controller as the guest network is not functioning at the moment. Will this upgrade somehow affect ap's?


Re: Upgrading WLC's

To download the code to the controller, the APs will not be affected. However, a reboot is required to load the new code, and when you reboot the WLC, the APs will disassociate.

When they reassociate, the APs will download the new code from the controller and reboot. This process takes several minutes, so schedule the appropriate amount of wireless network downtime.

Since APs can bounce around from controller to controller, make sure you're running the same version of code on every controller. If they're different, anytime an AP associates to a controller with different code it will need to go through the download process.

Is that what you're asking?


Hall of Fame Super Gold

Re: Upgrading WLC's

In addition to Jeff's comment, upgrade the backup controller first (if applicable). Rule of thumb in our network is to find a controller with the least amount of associated AP's and upgrade that FIRST. Then roll it across one by one.

Hall of Fame Super Gold

Re: Upgrading WLC's


Before I forget, from what firmware to what firmware do you intend to upgrade?

New Member

Re: Upgrading WLC's

Jeff & leolaohoo,

Thanks to both of you for suggestions. I am upgrading from >

Also to add to the thread:

I have 1 controller at our Data Center and 1 controller at our HQ. The ap's at each site are pointing to each other's controller's as secondary.

If I was to upgrade the DC controller, will the ap's in HQ (pointing to DC as secondary controller) try to get the updates and reboot or does that pertain to only ap's pointing to the primary?

Hope that makes sense.

Thanks again.


Re: Upgrading WLC's

In your situations, I believe the Cisco recommendation is:

- disable failback if you have it enabled (so that YOU control when AP's move back to their primary controller)

- Move DC AP's over to the HQ controller

- Upgrade the DC controller and reboot (all AP's are connected to the HQ controller and stay where they are)

- Move all AP's to the DC controller (at this point, all AP's will get the new firmware - this will take some time)

- Upgrade the HQ controller (all AP's are connected to the DC controller and stay where they are)

- Move the HQ AP's back to the HQ controller

Hall of Fame Super Gold

Re: Upgrading WLC's

Hi John,

"I am upgrading from >"

I do hope you are also upgrading the bootstrap accordingly.

"If I was to upgrade the DC controller, will the ap's in HQ (pointing to DC as secondary controller) try to get the updates"

No, the AP's won't do that. The AP's will only "swing" if the primary WLC's go down. The AP's primarily associated to the DC will "swing" to the HQ WLC until the DC WLC comes up. When this happens, the AP's will swing back, upgrade the IOS and reload.

If you are going to do multiple reboots to a WLC, I recommend that you enable the service port and disable the Management Interface. This will prevent the AP's from corrupting their IOS.

Otherwise, you'll have to upgrade, boot, wait for all of the AP's to join, upgrade their IOS, boot and then load the next firmware to the WLC. This will take alot of time.

Hope this helps.

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