Upgrading to 8.5.120.0

[CiaranB]

Hi there,

We currently have version 8.3.132.0 installed on 2 x WLC 8540 controllers in SSO mode, with 2000+ APs, a mix of 1700 and 2700 APs with a few 2800s also.

We are considering upgrading to version 8.5.120.0 at some point as we may want to use the new iPSK feature. Also, there appears to be some stability issues with 8.3.132.0 reloading the controller. I'm still trying to confirm if this affects 8540s as well as 5500.

I see the following in the release notes 8.5.120.0:

"The image format of Cisco Aironet 1700, 2700, 3700, and IW3702 APs has been changed from ap3g2 to c3700. Therefore, if you are upgrading to Release 8.5 or a later release from Release 8.3 or an earlier release, these APs will download the image twice and reboot twice."

What implications does this have in terms of AP downtime for our 2000+ APs during an upgrade? In previous upgrades we have preloaded the software onto the APs and greatly minimized the downtime needed.

Any feedback would be appreciated.

[Leo Laohoo · Accepted solution]

I can confirm that with 8.5.110.0 (and later), the 1700/2700/3700 will just download the firmware once and reboot once.
The behaviour described above is only for 8.5.107.0 and earlier. I suspect the reason for this is to test a way to stop the 1600/2600/3600 from getting supported with 8.6.

[Scott Fella]

Leo,

Are you sure about that?  If going from 8.3 to any 8.5, the x702’s will reboot twice. If you are already on 8.4 and later, you are okay. 

[Leo Laohoo]

Yes. I've been playing with it. I deliberately deleted the CAPWAP image of some APs (left only the RCV). When the APs rebooted, they downloaded the image once.
I've also noticed that with 8.5.110.0 (haven't checked with .120 but I'm sure it's the same), the naming convention of the filename for the 1700/2700/3700 have gone back to the "standard" prefix of "ap3g2" (instead of "c3700"). The APs that I've been testing have all been booting up to this IOS filename.

It might say in the 8.5.110.0 (and later) Release Notes that the APs will reboot twice but this is just poor documentation (and quality control).  

[CiaranB]

Hi again, 

We never got round to upgrading our production controller to a newer version, so we're still running 8.3.132.0.

We now plan on upgrading to version 8.5.140.0 to support a number of new access point models.

For the reasons outlined in my original post, can you confirm the access points will not reboot twice when upgrading to the new version of the software - the documentation still warns that it will. It's a little difficult for me to test in my environment, which i may post a separate question about.

thanks for your help,

Ciaran

[CiaranB]

I've just noticed that although version 8.5.140.0 is available forthe WLC8540, 8.5.135.0 is the recommended version.
I've read about some problems with 8.5.135.0 but i'm just not sure if that was with a different controller type.
Which would you go with?

thanks again
Ciaran

[Leo Laohoo · Accepted solution]

Go with 8.5.140.0.

[Scott Fella]

We are going with 8.5.140.0 but we also have not had issues with 8.5.135.0.