Troubleshooting Tip: HA out of sync due to Hardware Revision mismatch on FortiGate 90G

Description

This article describes an HA out-of-sync issue even though both HA units have the same hardware model and firmware version. 

Scope

FortiGate.

Solution

Under System -> HA, it shows that system.interface table is out of sync. Recalculating the checksum does not help. 

execute ha synchronize stop
execute ha synchronize start
diagnose sys ha checksum recalculate

Manually comparing the system interface settings on both HA units revealed that one unit has interfaces labeled as x1 and x2, while the other unit has interfaces labeled as port a and b. 

Example on one FortiGate showing x1 and x2 interfaces:

show system interface
config system interface
    edit "x1"
        set vdom "root"
    next
    edit "x2"
        set vdom "root"
    next
end 

Example on another FortiGate not showing x1 and x2:

show system interface
config system interface
    edit "a"
        set vdom "root"
    next
    edit "b"
        set vdom "root"
    next
end

Upon checking the hardware status, one HA unit is showing Revision 1 and the other HA unit is showing Revision 2. 

FortiGate-90G-01 # get hardware status
Model name: FortiGate-90G

ASIC version: SOC5

CPU: ARMv8

Number of CPUs: 8

RAM: 7548 MB

EMMC: 9982 MB(MLC) /dev/mmcblk0

Hard disk: not available

USB Flash: not available

Network Card chipset: FortiASIC NP7LITE Adapter (rev.)
Hardware Revision: Rev1

FortiGate-90G # get hardware status
Model name: FortiGate-90G

ASIC version: SOC5

CPU: ARMv8

Number of CPUs: 8

RAM: 7548 MB

EMMC: 9982 MB(MLC) /dev/mmcblk0

Hard disk: not available

USB Flash: not available

Network Card chipset: FortiASIC NP7LITE Adapter (rev.)
Hardware Revision: Rev2

The reason for HA out-of-sync is that FortiGate 90G revision 1 and revision 2 have different interface names. For more information, refer to this article: Technical Tip: Members of FortiLink interface on FortiGate 90G with different hardware revisions.

It is recommended that both units in the HA cluster use the same hardware revision to ensure consistency. FortiGate 90G/91G does not support HA formation between different generations: HA unsupported between different FortiGate 90G and 91G series hardware generations.

If aligning hardware revisions is not possible, consult a Fortinet Systems Engineer (SE) for further guidance.