: FortiOS 6.4.x is the absolute final major software line supported on the FortiGate 100D architecture.
Under the File Upload section, click and select the downloaded .out file corresponding to your next sequential step.
Download the .md5 file to ensure the image isn't corrupted. 3. Installation Methods Fortigate 100d Firmware Download BEST
Once this date passes, technical support and firmware access via official channels typically cease.
Before you download any firmware file, you must understand the hardware constraints of the FortiGate 100D. End of Engineering Support (EOES) : FortiOS 6
View your current build in the System Information widget on your dashboard.
Downloading firmware from unofficial sources (like torrents or third-party forums) poses a severe security risk as the files may contain backdoors. Upgrade Best Practices Upgrade Path Tool - Fortinet Document Library End of Engineering Support (EOES) View your current
If a critical zero-day vulnerability is discovered in FortiOS 6.2 today, the FortiGate 100D will likely not receive a patch.
Where to get firmware (safe, authoritative)
Use the Fortinet Upgrade Path Tool in the support portal. It tells you exactly which "hop" versions you must take.
Many engineers recommend the FortiOS 6.0.x branch (specifically 6.0.12 or later) for users who prioritize stability and low resource consumption over the newer features in 6.2.