Fortigate Firmware [extra Quality] (Free)

Title: The FortiOS Fortress: Anatomy, Evolution, and Strategic Importance of Fortigate Firmware

Backup Config: System > Config > Backup (Save as .conf file).
Check Hardware: Ensure you have sufficient free memory (CMDB) and disk space. Use diagnose sys top (if memory > 80%, delay upgrade).
Read Release Notes: Specifically look for "Known Issues" and "Upgrade Information" for your specific hardware model.
Download Firmware: You need a valid support contract. Download the exact file for your FortiGate model (e.g., FGT_100F-v7.4.5-FORTINET.out). Do not upload a 100F image to a 60F.

Upload: System > Firmware (or Maintenance > Firmware).
Manually upload the file from your PC.
Wait for the upload to verify (checksum validation).
Confirm upgrade. The FortiGate will reboot. The Ethernet link may drop.
Wait until the login screen appears (Check console or ping).
Verify: Log in, check System > Dashboard > Summary for the new version.
Repeat the next step in the upgrade path until you hit your target.

Interception: When a client initiates an HTTPS connection, the FortiGate intercepts the handshake.
Decryption: The FortiGate uses a locally stored Certificate Authority (CA) certificate (imported into the client's browser) to generate a certificate on the fly for the destination site. This allows the FortiGate to decrypt the session content.
Inspection: The decrypted traffic is passed through the full security stack (Antivirus, IPS, Web Filtering, Application Control) to identify threats.
Re-encryption: Once cleared, the traffic is re-encrypted and forwarded to the destination server.
Delivery: The content is delivered to the client, usually with the source IP preserved via NAT.

Cause:

Old logs or antivirus definitions are clogging the flash disk. Fix: SSH into the FortiGate. Run execute formatlogdisk (clears logs, not config) or exec factoryreset (last resort).

Upload image and execute upgrade:

Custom scripts or automation