COMMUNICATION SYSTEM, COMMUNICATION METHOD, NETWORK DEVICE AND PROGRAM
An object of the present disclosure is to transfer unicast via a boundary apparatus that is geographically close to a user apparatus even in communication from an L2 network to an EVPN and to prevent overlapping distribution of BUM. According to the present disclosure, there is provided a communication system in which a first network and a second network are connected to each other by a plurality of paths, in which, in the plurality of paths, a transfer prevention unit that prevents transfer of a broadcast frame, an unknown unicast frame, and a multicast frame from the second network to the first network is included, and in which a broadcast frame, an unknown unicast frame, and a multicast frame are transferred from the second network to the first network by only a specific path of the plurality of paths.
1 . A communication system in which a first network and a second network are connected to each other by a plurality of paths, the communication system comprising:
in the plurality of paths, a transfer prevention unit, including one or more processors, configured to prevent transfer of a broadcast frame, an unknown unicast frame, and a multicast frame from the second network to the first network, wherein:
the transfer prevention unit is disabled by only a specific path of the plurality of paths, and a broadcast frame, an unknown unicast frame, and a multicast frame are transferred from the second network to the first network by only a specific path of the plurality of paths.
2 . The communication system according to claim 1 , wherein
the first network is an Ethernet virtual private network (EVPN),
the second network is an L2 network, and
the specific path is determined by using a designated forwarder (DF) function of the EVPN.
3 . The communication system according to claim 1 , further comprising:
a network apparatus provided on the plurality of paths comprising:
a BUM passing/non-passing determination unit, including one or more processors, configured to acquire identification information of a network apparatus provided at a boundary between the first network and the second network via the first network, and determines enabling of the transfer prevention unit by using the acquired information, and
a transfer prevention enabling unit, including one or more processors, configured to enable the transfer prevention unit according to the determination by the BUM passing/non-passing determination unit.
4 . The communication system according to claim 3 , wherein
in at least one path of the plurality of paths,
a first network apparatus connected to the first network and a second network apparatus connected to the second network are connected to each other,
the first network apparatus includes the BUM passing/non-passing determination unit, and
the second network apparatus includes the transfer prevention enabling unit and the transfer prevention unit.
5 . A communication method executed by a communication system in which a first network and a second network are connected to each other by a plurality of network apparatuses, the method comprising:
disabling, by only a specific path of the plurality of paths, a transfer prevention unit that prevents transfer of a broadcast frame, an unknown unicast frame, and a multicast frame from the second network to the first network, the transfer prevention unit being included in the plurality of paths; and
transferring a broadcast frame, an unknown unicast frame, and a multicast frame from the second network to the first network by only a specific path of the plurality of paths.
6 . A network apparatus connected to a boundary between a first network and a second network, the network apparatus comprising:
a transfer prevention unit, including one or more processors, configured to prevent transfer of a broadcast frame, an unknown unicast frame, and a multicast frame from the second network to the first network;
a BUM passing/non-passing determination unit, including one or more processors, configured to acquire identification information of a network apparatus provided at a boundary between the first network and the second network via the first network, and determines enabling of the transfer prevention unit by using the acquired information; and
a transfer prevention enabling unit, including one or more processors, configured to enable the transfer prevention unit according to the determination by the BUM passing/non-passing determination unit.
7 . The network apparatus according to claim 6 , wherein
the first network is an EVPN, and
the BUM passing/non-passing determination unit determines enabling of the transfer prevention unit by using a DF function of the EVPN.
8 . A non-transitory computer-readable storage medium storing a program for causing a computer to function as each functional unit included in the network apparatus according to claim 6 .
9 . A non-transitory computer-readable storage medium storing a program for causing a computer to function as each functional unit included in the network apparatus according to claim 7 .
10 . The communication method according to claim 5 , wherein:
the first network is an Ethernet virtual private network (EVPN),
the second network is an L2 network, and
the specific path is determined by using a designated forwarder (DF) function of the EVPN.