A FortiManager unit can also perform firmware updates for multiple FortiGate units, saving time rather than upgrading each FortiGate unit individually.
The FortiManager unit stores local copies of firmware images, either by downloading images from the Fortinet Distribution Network (FDN) or by accepting firmware images that are uploaded from the management computer.
If you are using the FortiManager unit to download firmware images, the FDN first validates device licenses and support contracts and then provides a list of currently available firmware images. For devices with valid Fortinet Technical Support contracts, you can download new firmware images from the FDN and the firmware release notes.
After firmware images have been either downloaded from the FDN or imported to the firmware list, you can either schedule or immediately upgrade/downgrade a device or group of device’s firmware.
See the FortiManager Administration Guide for more information on updating the FortiGate firmware using the FortiManager central management.