I recently had to update the firmware on 2 UCS 6120XPs FIs that were on different firmware versions at the UCS Manager(USCM, also called system) level of the interconnects.
My first step was to erase the configs on each interconnect and setup was rerun to configure the FIs in "stand-alone" mode. Also the firmware packages were already loaded to the servers via the GUI(Please refer to the CLI documentation for steps on erasing the configuration and uploading firmware images). To update the firmware via the CLI I used the following steps: