Upgrading WLC from 8.2.166.0 to 8.5.140.0

[Andrew White]

Hello,

So it looks like I can upgrade 8.2.166.0 to 8.5.140.0 in one go, however there seems to be 4 files that I can download.

https://software.cisco.com/download/home/282600534/type/280926587/release/8.5.140.0

We have 2 x 5508s and 27 APs and I upgrade about a year ago, but I'm sure I just upload a single file from my PC to the WLC via the GUI and it then upgrade the Active WLC then the Standby WLC and rebooted the APs after?

Any ideas on this process and the file(s) required?

Thanks

[Andrew White]

I hope to reboot both WLC's this weekend, but worried what could go wrong. Many access points in remote offices too.

[Sathiyanarayanan Ravindran]

You can use pre-image download option to avoid any issues. Right now you have uploaded the image in to your WLCs . So now you can use the option pre image download option to upload the os prior to the reboot of WLC. For that you have to go to wireless -> global configuration and pre image download.

So that aps will have the OS which you are upgrading to controller prior to the activity so that you can have a minimum downtime and no issue on upgrade.

Please refer below link for pre image download

https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-3/config-guide/b_cg83/b_cg83_chapter_0101.html#ID1225

[Andrew White]

Thanks so download image then choose interchange?

[Sathiyanarayanan Ravindran]

Yes

[sivamalleswararao]

we are using 2504 WLC with 8.2.166.0 firmware. I am getting packet drops in all the access points (Aironet 1832 series) at a time. can somebody help me out to solve this