What is AP Image Preload and how it works in Aruba OS?

Aruba Employee
Aruba Employee
Pre 6.3.x:

when the AOS image on the controller is upgraded, the AP's associated to this controller download their images after the controller reboots and comes up with the new image. Once the AP downloads the new image, it needs to reboot and complete the AP boot process (network discovery, connect to LMS IP, check image and config, build PAPI/GRE tunnels to LMS) before it can become operational and start serving WLAN clients.
From 6.3.x:

The AP Image Preload feature minimizes the downtime required for a controller upgrade by allowing the APs associated to that controller to download the new images BEFORE the controller actually boots with the new image.
After the new image has been downloaded on the controller, an AP can download (preload) its new image while serving clients at the same time. After the download has been completed, the AP notifies the controller on the success/failure of the download. In the case of a failure, the AP attempts to download the image after a brief waiting period.
If AP Image Preload is enabled and a new AP joins the controller, the controller checks if the AP's name or group is listed in the preload list. If the AP is on the list and does not already have the specified image in it's Flash memory, it will start preloading this image.
Note: AP Image Preload is supported on the 3600, M3 and 7200 series platforms.



Environment : This Article applies from AOS 6.3.x and supported only on the 3400, 3600, M3 and 7200 series platforms.


Configuration Steps :


Configuration required for AP Image Preload:
Enable AP Image Preload
- Select APs: It is possible to choose selective APs for Image Preload. APs can be specified as follows:
- All APs associated to the controller
- A list of AP Groups
- Individual APs (by 'ap-name')

Based on the existing load on the controller, it is possible to specify how many APs can simultaneously preload their image.
CLI Configuration





GUI Configuration:

1. Login to controller GUI
2. Navigate to Maintenance - WLAN - Preload AP Image
3. Select the Radio Button "yes" for AP IMAGE PRELOAD
4. Select the AP partition (partition 0 or partition 1)
5. Select "All AP's" - To apply the feature for all the AP's or select "specific AP's" - To implement the feature only for few AP's
Verification : To Verify the status, please execute the command "show ap image-preload-status"



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Last update:
‎08-21-2014 12:24 PM
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