topic Re: WLC Software Upgrade Predownload Failed in Wireless

WLC Software Upgrade Predownload Failed

jmorton1 — Tue, 29 Jul 2025 10:59:04 GMT

I am looking to upgrade our wireless controller from version 17.9.6 to 17.9.7. I selected the option to do the AP Image Predownload, and the predownload failed on 13/45 of our APs. Does this mean that if I were to download and install or save and activate that those 13 aps will fail to get the new software?

Is this something for which I need to engage TAC? Thanks in advance for your advice,

Re: WLC Software Upgrade Predownload Failed

Enes Simnica — Tue, 29 Jul 2025 11:04:04 GMT

hello @jmorton1. from what u described and from the screenshot aka png image, i can say that the failed predownload on 13/45 APs means those APs didn’t get the new image in advance, but they’ll still attempt to upgrade during the actual activation. Because often, APs recover during the main upgrade process. Proceed with the install/activate, but monitor the APs closely. If the 13 APs fail to come back online after activation, check their logs (show ap summary or show ap name stats...) for issues like connectivity or image corruption. If problems persist, then u have to engage Cisco TAC. hope it helps and also check this: https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-2/config-guide/b_wl_17_2_cg/b_wl_17_2_cg_chapter_010010111.html

-Enes

Re: WLC Software Upgrade Predownload Failed

Leo Laohoo — Tue, 27 Jan 2026 00:37:52 GMT

@jmorton1 wrote:
I am looking to upgrade our wireless controller from version 17.9.6 to 17.9.7.

And I know the reason(s) why the AP failed pre-download: CSCwe15172, CSCwe97901, CSCwm08044, CSCwm07499, CSCwm72142, CSCwo05017, CSCws77337.

Allow me to provide a "summary" of the three bugs (above) draw the line as to why the APs failed pre-download:

1. All three bugs have one thing in common: AP's /tmp folder gets bloated that the flash hits 100% and, subsequently, causes the AP to crash.

2. When the APs hit the bug, nothing gets written into the flash. NOTHING. Including, pre-downloaded firmware.

The solution, unfortunately, is: Reboot ALL APs before the start of the firmware upgrade. Reboot ALL APs before starting pre-download.

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Tue, 29 Jul 2025 11:23:31 GMT

Thanks for those links.

If I do need to reboot all the APs before the upgrade, then do I need to hit "rollback" on this screen and restart the process? Or do you think I simply reboot the APs and then click to Download and Install?

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Tue, 29 Jul 2025 11:23:53 GMT

Thanks for the quick reply and the links.

Re: WLC Software Upgrade Predownload Failed

MHM Cisco World — Tue, 29 Jul 2025 11:27:49 GMT

Use cli to check issue

First step

Show ap image

Check which AP fialed to install image

Then use

Show ap summary

Check mac of ap and model

It can image you use not compatible with all AP ypu have

MHM

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Tue, 29 Jul 2025 11:33:48 GMT

Thank you for the suggestion. All of our APs are the exact same model, but I did find that for some reason 13 of the APs had some backup image loaded on them, so it would appear to be an issue with space on those APs.

Any thoughts as to how to clear the space on those APs?

Re: WLC Software Upgrade Predownload Failed

Mark Elsen — Tue, 29 Jul 2025 11:40:02 GMT

- @jmorton1 As a side note ; any reason why staying on 17.9.x because it is getting old :
https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-xe-17/ios-xe-17-9-x-eol.html
Current advisory releases are 17.12.5 (if you still have the older IOS ap models) or
17.15.3

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Tue, 29 Jul 2025 11:44:33 GMT

Thank you. We have stayed on 17.9 because we are running into issues with ISE on newer versions of the WLC. We had it on version 17.12.X, but for some reason the wireless endpoints were not updating their NAC state in ISE, so they would be connected, but ISE would not show them as if they were connected.

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Tue, 29 Jul 2025 11:45:57 GMT

Going to version 17.9.5 (the latest in the 17.9.x at the time) was a recommendation from TAC actually. Then again, this was at least 1 years and a half ago, so obviously that has changed.

Re: WLC Software Upgrade Predownload Failed

Leo Laohoo — Tue, 29 Jul 2025 12:08:41 GMT

@jmorton1 wrote:
Or do you think I simply reboot the APs and then click to Download and Install?

Yes.

Re: WLC Software Upgrade Predownload Failed

Mark Elsen — Tue, 29 Jul 2025 15:35:07 GMT

- @jmorton1 Ok , as far as compatibility with ISE is concerned, make sure that the ISE version being used is not too old (e.g.)

Re: WLC Software Upgrade Predownload Failed

MHM Cisco World — Wed, 30 Jul 2025 11:19:46 GMT

Image is push to all same AP

Some success other not'

1- check if wlc push image to all or not' it can wlc cpu busy so some not get image intime' to check that

Do show ap summary/show ap image

Select only one ap and then use cli command to predown for only this AP if it success then try use regex (name of AP) to push image to group by group of AP

2- do above and failed' check memory in AP' I check yesterday there is no command or via gui we can check ap memory from wlc' you need to access AP and check memory (ypu must already know what is size of image)

MHM

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Mon, 18 Aug 2025 13:18:05 GMT

The solution was a combination of the replies given by @Leo Laohoo and @Enes Simnica. I rebooted all the APs as @Leo Laohoo recommended and then proceeded with the upgrade as @Enes Simnica recommended, and is worked just fine.

I also ran the commands recommended by @MHM Cisco World and found out why 13 of the APs failed predownload. Those 13 APs had a backup image saved to the device from a previous upgrade, and I am thinking those 13 APs may be older and thus have had more time to go through more upgrades.

Thank you to everyone who replied!

Re: WLC Software Upgrade Predownload Failed

jmorton1 — Mon, 18 Aug 2025 15:52:06 GMT

So I just upgraded to version 17.15.4 and the NAC status is working fine now. Thank you.