: The final supported branch for the FortiGate 100D is FortiOS 6.2 . The absolute final release engineered for this hardware is FortiOS 6.2.15 . 📥 Where to Safely Download FortiGate 100D Firmware
The FortiGate 100D model officially reached its on July 26, 2023 . This date is a hard stop: Fortinet no longer provides official technical support, hardware RMA services, or, most critically, new security patches for the device. After nearly a decade of service (initial release dates back to ~2014), the platform is fully retired. Fortigate 100d Firmware Download BEST
Do download firmware from:
The is an older hardware model that has reached its maximum supported firmware version. The best and final stable firmware for this device is FortiOS 6.2.15 . 🛠️ Firmware Compatibility & Selection : The final supported branch for the FortiGate
Since you cannot patch security holes in routing mode, consider resetting the 100D to (Layer 2). This limits attack surfaces and turns the device into a basic inspection bridge. This date is a hard stop: Fortinet no
| FortiOS Version | Build | Status | Why choose it? | RAM Usage | | :--- | :--- | :--- | :--- | :--- | | | 6.0.15.0330 | Recommended | Most stable; final patch for 6.0 branch; all security fixes without 6.2’s memory leaks. | ~45% idle | | 6.2.10 | 6.2.10.1923 | Alternative | Last version ever for 100D. Includes features like Security Fabric rating, but can be heavy on RAM (may cause conserve mode). | ~65% idle | | 5.6.13 | 5.6.13.0715 | Legacy Only | Use only if upgrading from 5.4. You must pass through this. | ~30% idle |