After installing FortiOS v7.2 on a FortiGate 70G running BIOS 0600020X, the device consistently stops at the 'Initializing firewall…' stage during boot and does not proceed any further.
When the same FortiOS releases are used with an older BIOS (0600010X), the FortiGate 70G boots normally with no hang observed.
To check the BIOS version:
get system status | grep BIOS
BIOS version: 06000202
Here, 06000202 is the affected BIOS version.
Example console log from TFTP install on an affected unit:
Image Received.
Checking image... OK
This firmware image is certified.
Save as Default firmware/Backup firmware/Run image without saving:[D/B/R]?D
Programming the boot device now... OK
Verifying... OK
Booting OS...
Initializing firewall...
      After the 'Initializing firewall…' message appears on an affected system, there is no further console output. The device does not complete the startup sequence, and it does not become reachable.
The issue is not triggered by any particular upgrade method. It occurs both after device format and loading an affected version, or after a downgrade from an unaffected version to an affected version.
This behavior has only been observed on FortiGate 70G devices running FortiOS v7.2 together with a 0600020X BIOS version. It has not been reported on devices running v7.4 firmware or devices with an older 0600010X BIOS version.
Fortinet has fixed the issue and released a revised image for FortiOS v7.2.13 for FortiGate-70G to the Fortinet Support Portal. The revised build number is build 6691. Contact Fortinet Support if the device is FortiGate-71G.
To install the special image, follow the steps outlined in the following article: Technical Tip: Formatting and loading FortiGate firmware image using TFTP.
Note: Although support for SSL VPN is removed in v7.2.13 for G models, this special build still supports SSL VPN in both tunnel and web modes.
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