There is provided an apparatus for performing loop-free transmission in a communication network. The apparatus includes a plurality of ports, a controller, a memory, and an interface unit. The controller generates monitoring frames that are transmitted to another apparatus, so as to monitor a connection state of the communication network. The memory includes port-state information that stores a port state in association with each of the plurality of ports. The interface unit processes a frame based on the port-state information and sets, in the port-state information, a stopped state to a first port included in the plurality of ports, in accordance with a time period during which the monitoring frames are not generated. The interface unit discards a frame received via the first port for which the stopped state is set in the port-state information.