4000 Router Series IP Multicast Configuration Guide

Multicast application in VPNs

A PE device that supports multicast for VPNs does the following operations:

• Maintains an independent set of multicast forwarding mechanisms for each VPN, including the

multicast protocols, PIM neighbor information, and multicast routing table. In a VPN, the device

forwards multicast data based on the forwarding table or routing table for that VPN.

• Implements the isolation between different VPNs.

• Implements information exchange and data conversion between the public network and VPN

instances.

As shown in Figure 10, w

hen a multicast source in VPN A sends a multicast stream to a multicast group,

only the receivers that belong to both the multicast group and VPN A can receive the multicast stream.

The multicast data is multicast both in VPN A and on the public network.