MULTICAST NETWORK SYSTEM, RELAY DEVICE, PROGRAM, AND DISTRIBUTION DEVICE CANDIDATE INFORMATION TRANSMISSION METHOD OF RELAY DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce a distribution device candidate message size when adopting a redundant configuration of a distribution device.SOLUTION: A multicast network system includes: a plurality of relay devices forming a distribution route of a multicast packet to a multicast group and including two or more distribution device candidates which may become a distribution device for distributing the multicast packet; and a notification device which distributes a distribution device candidate message received from each of the two or more distribution device candidates and including distribution device candidate information to the relay devices. Each of the distribution device candidates includes a control section by which, if distribution device candidate information of another distribution device candidate more preferential than a present device regarding the multicast group is included in the distribution device candidate message received from the notification device, distribution device candidate information of the present device is excluded from a target of transmission to the notification device and if not, the distribution device candidate information of the present device is transmitted to the notification device.