What happens if you create an ADOM with version 7.2, add FortiGate devices running FortiOS 7.2, and then upgrade the FortiGate devices to FortiOS 7.4?

A FortiManager Administrative Domain (ADOM) is designed to manage multiple devices, which can be running different supported firmware versions simultaneously. When a managed FortiGate device is upgraded to a firmware version (FortiOS 7.4) that is higher than the ADOM's configured version (7.2), the device remains within the ADOM. The ADOM continues to manage this device, but the available management features will be limited to those supported by the ADOM's version (7.2). To manage the new features of FortiOS 7.4, the ADOM itself must be manually upgraded. Therefore, the ADOM will be concurrently managing devices running both FortiOS 7.2 and 7.4.

B. Adding higher version FortiGate devices to a lower version ADOM triggers an automatic ADOM upgrade.

ADOM upgrades are a deliberate, manual administrative process and are never triggered automatically by a device firmware change to prevent unintended configuration issues.

C. The ADOM restricts access to devices running lower firmware versions.

This is incorrect. ADOMs are backward-compatible; a 7.2 ADOM is fully capable of managing devices with lower firmware versions (e.g., 7.0) without restriction.

D. Upgrading the FortiGate devices to FortiOS 7.4 may result in ADOM database corruption.

This is not the designed or expected behavior. FortiManager is built to handle such version mismatches gracefully by limiting feature visibility, not by corrupting its database.

1. Fortinet FortiManager Administration Guide 7.4.0

"Administrative Domains (ADOMs) > ADOM versions"

Page 108.

The documentation states

"You can manage multiple devices with different FortiOS versions in the same ADOM. When you set the ADOM firmware version

you are setting the firmware features that can be managed for all devices in the ADOM." This directly supports that an ADOM can concurrently manage different versions.

2. Fortinet FortiManager Administration Guide 7.4.0

"Administrative Domains (ADOMs) > Upgrading an ADOM"

Page 110.

The guide explains

"When you upgrade the firmware of a managed device

you should also upgrade the ADOM version to match the device firmware version. This ensures that you can manage all the features of the device." This implies that if the ADOM is not upgraded

the device remains manageable but with a limited feature set

confirming that the ADOM continues to function with mixed versions. The process described is manual

refuting option B.