F5 BIG-IP - Changing boot image from 13.x to 15.x

Hi all,

Is it possible to change the boot image for an F5 BIG-IP from version 13.x to 15.x? I have config on this F5 in a test environment, I want to switch the version 15.x (which is already installed and ready to use on it) but I'm worried I'll lose config/connectivity if I do this.

Anybody done this before?

Thanks