Patent ID: 7751394
Filing Date: 2010-07-06
Classification: H04L

Abstract:
1. A packet relay device in which both a function of multiple virtual routers and multicast routing are implementable, comprising a line interface which accommodates a communication line, a packet transfer function unit which transfers a received packet, a memory unit, and a control unit, wherein, said memory unit stores, with respect to each of the virtual routers, upstream virtual router information indicating a virtual router which receives a multicast packet from another packet relay device, and a multicast routing table which is used for transmitting the multicast packet, said control unit has a function which sets up said upstream virtual router information and said multicast routing table, said upstream virtual router information is provided with a first field to store a multicast group address indicating a transfer destination of the multicast packet received from said line interface, and a second field to store identification information of the virtual router which receives the multicast packet, said multicast routing table is provided with a first field to store a multicast group address indicating a transfer destination of the multicast packet received from said line interface, and a second field to store identification information of multiple line interfaces to transmit the multicast packet thereto, and a line interface indicated by the identification information of the multiple line interfaces in the second field of said multicast routing table is not limited to a line interface belonging to the virtual router which has received the multicast packet.