Patent ID: 8442045
Filing Date: 2013-05-14
Classification: H04L

Abstract:
1. A method of forwarding an IP packet through a logical chassis, comprising: designating a first egress port, which is not a member of a stacked link aggregation group associated with a first physical chassis, to be a layer-3 member of a multicast group; designating a second egress port, which is a member of the stacked link aggregation group associated with the first physical chassis, to be a layer-2 member of the multicast group; the first physical chassis receiving a multicast IP packet and performing a first layer-3 lookup operation which identifies a next hop as the first egress port and the second egress port; making a copy of the multicast IP packet for each of the first and second egress ports and sending a first copy of the multicast IP packet to the first egress port and sending a second copy of the multicast IP packet to the second egress port; the first egress port receiving the first copy of the multicast IP packet and forwarding it to a next hop; and the second egress port receiving the second copy of the multicast IP packet and switching it out over the stacked link aggregation group unchanged to a second physical chassis.