Multicast over Layer 3 VPNs
The JUNOS software provides support for IP version 4 (IPv4) multicast over Layer 3 virtual private networks (VPNs), as described in RFC 2547, BGP/MPLS VPNs. The implementation is based on Section Two of the IETF Internet draft draft-rosen-vpn-mcast-06.txt, Multicast in MPLS/BGP VPNs (expires April 2004) and uses Protocol Independent Multicast (PIM) and generic routing encapsulation (GRE) tunneling. Initially, only PIM sparse mode was supported. However, Layer 3 VPN multicast support now also includes PIM dense mode and the Multicast Source Discovery Protocol (MSDP).
This document assumes the reader is familiar with Layer 3 VPN operation on Juniper Networks routers, as well as standard PIM configurations. For more information on PIM and MSDP and their usage in a Layer 3 VPN, see the JUNOS Multicast Protocols Configuration Guide. For more information on Layer 3 VPN configuration, see the JUNOS VPNs Configuration Guide. Both manuals are located at
http://www.juniper.net/techpubs/software/index.html.