Controller Based WLANs

Q:

What are the MSM7XX Code Upgrade & Downgrade rules to follow?

Rules for MSM upgrades:

It is always a best practice to backup the MSM controller's configuration before you upgrade to a newer version or downgrade to an older version of software.
 

From the GUI:

Controller -- Maintenance -- Config File Management -- Backup configuration

But, it is good to know that when you upgrade your MSM controller from your current code version to a newer one,  the configuration for your current code version will be kept in storage on the controller (config.recovery.gz)

For example:

If you upgrade from version 6.6.5 to 6.6.9, the 6.6.5 configuration will be saved. So, if you decide to downgrade to version 6.6.5 your configuration will still be available. Furthermore, once you do the downgrade, the higher version, 6.6.9, will now be stored in config.recovery.gz. If you downgrade to 6.6.7 , from 6.6.9, instead, you will have lost the 6.6.5 software configuration.

Basically, implementing any upgrade or downgrade software image to the controller, the most recent software image configuration will be saved.