Restricting the type of frames allowed through IEEE 802.1Q ports
You can now specify whether each FortiSwitch port discards tagged 802.1Q frames or untagged 802.1Q frames or allows all frames access to the port. By default, all frames have access to each FortiSwitch port.
Use the following CLI commands:
config switch-controller managed-switch <SN>
config ports
edit <port_name>
set discard-mode <none | all-tagged | all-untagged>
next
next
end