FortiSwitch not Applying Configuration from FortiGate

Do you have FortiSwitches that do not accept configuration changes made on the FortiGate switch controller? Also, when you run the CLI command ‘execute switch-controller get-conn-status’, do you see the ‘flag’ with a value of ‘E’?

FGT01 # execute switch-controller get-conn-status
Managed-devices in current vdom root:

FortiLink interface : fortilink
SWITCH-ID         VERSION           STATUS         FLAG   ADDRESS              JOIN-TIME            SERIAL
Switch-A     v7.4.2 (801)      Authorized/Up   2E   10.10.10.1       Fri Jul 19 14:17:21 2024    S648FN1X12345678
Switch-B     v7.4.2 (801)      Authorized/Up   2E   10.10.10.2       Fri Jul 19 12:26:19 2024    S648FN1X12345679

         Flags: C=config sync, U=upgrading, S=staged, D=delayed reboot pending, E=config sync error, 2=L2, 3=L3, V=VXLAN, T=tunnel, X=External
         Managed-Switches: 2 (UP: 2 DOWN: 0 MAX: 24)

Try to execute the CLI command “execute switch-controller get-sync-status all”. You may also have the error “REST API login failed with error 60” visible there:

FGT01 # execute switch-controller get-sync-status all
Managed-devices in current vdom root:

FortiLink interface : fortilink
SWITCH-ID (SERIAL)                    STATUS CONFIG         MAC-SYNC       HTTP-UPGRADE
Switch-A (S648FN1X12345678)      Up     Error          Error          -

[1]
 command: https://10.10.10.1:443/api/v2/login
 payload:
 result : REST API login failed with error 60
Switch-B (S648FN1X12345679)      Up     Error          Error          -

[1]
 command: https://10.10.10.2:443/api/v2/login
 payload:
 result : REST API login failed with error 60

We have seen several instances of this problem under FortiOS 7.4.4 and 7.4.5 and you may also be one of the affected customers.

Peter was able to find a solution for the problem and has shared it in the commends below:

config switch-controller system
    set tunnel-mode compatible
end