iPhone could not connect internet when wireless controller enable Fast Transition

[Pengchen0124]

Hi guys , We are running cisco 3504 wireless controller with software version 8.5.105.0. and our co-workers using iPhone X told us when we enable fast transition on wireless controller, they will fail to connect internet. and to test this issue, i disabled the FT , all the iPhone users could connect internet normally.

does anybody have this problem? and how to fix this, thanks in advance.

[Pengchen0124]

Hi Patoberli
Many thanks for your kindly and clearly explanation.
could you please tell me more about emergency image? since in my opinion, wlc already has backup image, why still need ermergency image ? and what will trigger emergency image to work ? thanks again.

[patoberli]

The emergency image is similar to a boot loader. If you attach a console to the WLC and reboot it, you can start it in the bootloader (emergency image), which allows you to start with the Primary or Backup image for emergency cases.

More info:

https://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/107530-backup-image-wlc.html

[Scott Fella]

Emergency image is like a special image you get from TAC or the BU. These images have fixes in them but are not currently published and available for general downloads. You would need to open a TAC case and they would have to provide you with the image file. TAC would also help in identifying if you are hitting a bug or possibly even file a new bug if discovered.