Network system and communication apparatus for performing communication among networks having different VLAN settings

摘要

A network system that comprises a plurality of communication apparatuses, each of the communication apparatuses being capable of performing a VLAN setting by using a VLAN number set for a connection port, that sets a VLAN number for each of the communication apparatuses, and that performs communication among cars of a train, wherein in a case where a specific type of packet that disables a VLAN setting is a packet of a multicast address, when a distribution target apparatus is connected to a communication apparatus that has received the specific type of packet, the communication apparatus transfers the specific type of packet to the distribution target apparatus and, irrespective of a VLAN number set for another communication apparatus, regards a VLAN different from a VLAN of the communication apparatus as a same network and transfers the specific type of packet to the another communication apparatus.