During the infrastructure firmware upgrade stage using the Auto Install feature, the I/O module is upgraded.
The infrastructure firmware upgrade includes updates to the fabric interconnects and I/O modules, which are essential components of the UCS B-Series chassis network connectivity.
References: This information can be found in the Cisco UCS Manager Firmware Management Guide, which details the process and components involved in the firmware upgrade of Cisco UCS B-Series chassis.
https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/ucs-manager/GUI-User-Guides/Firmware-Mgmt/
https://www.youtube.com/watch?v=g-4OgYigvRI
