You can upgrade the firmware of an operating cluster using the GUI or CLI of the primary unit.
Similar to upgrading the firmware of a standalone unit, normal operations are temporarily interrupted during the cluster firmware upgrade. Therefore, you should upgrade the firmware during a maintenance window.
- Log into the GUI of the primary unit using the
- Upgrade the primary unit firmware. The upgrade is automatically synchronized between the primary device and backup devices.
It is recommended to view the console log output during upgrade. See Checking FortiManager log output.
Administrators may not be able to connect to the GUI until the upgrade synchronization process is completed. During the upgrade, SSH or telnet connections to the CLI may also be slow. You can still use the console to connect to the CLI of the primary device.