If you are using KVM to login to the Linux server or the EFI shell to update the firmware version of CIMC, when you run the activate command, the connection to CIMC is reset. As a result, the network connection is interrupted and the KVM window closes. https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c/sw/fwp/user/guide/Firmware_Upg rade_Utility/Using.html