This article describes how to recover the synchronization configuration from a FortiSwitch showing the 2E flag constantly.
Scope
FortiSwitch v7.4.2 and earlier versions.
Solution
When a network disruption or NTP communication has been lost, the E flag sometimes persists in FortiSwitch devices, preventing them from synchronizing configuration with FortiGate:
execute switch-controller get-conn-status FortiLink interface : fortilink SWITCH-ID VERSION STATUS FLAG ADDRESS JOIN-TIME SERIAL P3-DITC-5 v7.4.2 (801) Authorized/Up 2E 169.254.1.8 Tue Jan 30 18:26:24 2024 S448EFTF23009061 P3-DITC-3 v7.4.2 (801) Authorized/Up 2E 169.254.1.6 Tue Jan 30 18:27:14 2024 S448EFTF23008816 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: 74 (UP: 71 DOWN: 3 MAX: 196)
To fix this issue, clear the E state:
config switch-controller lldp-settings set device-detection disable end
Re-enabling device-detection will allow all switches to enter the sync state:
config switch-controller lldp-settings set device-detection enable end
This issue is resolved in FortiSwitch v7.4.3 and above. Consider upgrading FortiSwitch.