WLC 5508 AP SSO FUS Upgrade with different Versions

[Marc Aemmer]

Hi everybody,

I've got two 5508 configured as AP SSO and I want to upgrade the FUS to 1.9.0.0
The Image running is 7.6.110.0

On the active controller the FUS Version is 1.3
On the HA-SKU controller the FUS Version is 1.7

Now, can I upgrade the FUS to 1.9.0.0 using the GUI, even when both controllers don't use the same FUS Version? If yes, can I go directly from FUS 1.3 to 1.9.0.0?

thanks a lot,
marc

[Leo Laohoo]

On the active controller the FUS Version is 1.3

You may need to break HA and upgrade the active controller to FUS 1.7.  Once the active controller is upgraded to this version, you enable HA.  Only then can you upgrade the pair to 1.9 via GUI.  And when you do this, the active controller will "push" the FUS 1.9 to the hot-standby unit independently.

[Marc Aemmer]

What about the following procedure:

1. Upgrade FUS to 1.9.0.0 on Standby via CLI.

2. force-switchover active role to upgraded standby controller.

3. Upgrade FUS to 1.9.0.0 on the standby controller (active before) via CLI.

4. force-switchover back to initial situation.

So there is a minimal downtime for the AP's (Just when switchover twice)

[Sandeep Choudhary]

Hi,

Your process could work but I am not sure.

To be 100% sure then You must break HA. Upgrade FUS and then join again.

Regards

Dont forget to rate helpful posts

[Marc Aemmer]

Unfortunately its not possible to upgrade just the standby controller in a AP SSO setup. The Command "transfer" is not available on the controller with the standby role. :-/

I don't get it, why it's not possible to upgrade either FUS oder Software in a AP SSO setup without downtime. The reason why people use AP SSO is because they have a sensitive wireless environment (24/7) and care about not having some downtime. Hopefully there will give some improvements in future releases in case of downtimes when upgrading.

[Leo Laohoo]

1. Upgrade FUS to 1.9.0.0 on Standby via CLI.

I do not believe it is a good idea to go from FUS 1.3 to FUS 1.9 without going through FUS 1.7.

[Marc Aemmer]

Unfortunately its not possible to upgrade just the standby controller in a AP SSO setup. The Command "transfer" is not available on the controller with the standby role. :-/

I don't get it, why it's not possible to upgrade either FUS oder Software in a AP SSO setup without downtime. The reason why people use AP SSO is because they have a sensitive wireless environment (24/7) and care about not having some downtime. Hopefully there will give some improvements in future releases in case of downtimes when upgrading.