STP forwarding

By default, the FortiGate does not forward Spanning Tree Protocol (STP) bridge protocol data units (BPDUs). If you require STP forwarding, in most configurations you must enable STP forwarding on the interface. If your FortiGate is in one-armed sniffer mode, you must instead enable STP forwarding mode on the interface.

Layer 2 loops may occur if STP is broken due to the FortiGate blocking STP BPDUs.

STP forwarding on the interface

To enable STP forwarding on an interface, use the following CLI command:

config system interface

edit <interface_name>

set stpforward enable

next

end

STP forwarding mode

STP forwarding mode is an additional option that you use for STP handing when your FortiGate in one-armed sniffer mode. To configure STP forwarding mode, use the following CLI command:

config system interface

edit <interface_name>

set stpforward-mode {rpl-all-ext-id | rpl-bridge-ext-id | rpl-nothing}

next

end