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 (expired April 2004) and uses Protocol Independent Multicast (PIM) and generic routing encapsulation (GRE) tunneling. Initially, only PIM sparse mode was supported. In JUNOS Release 5.5 and later, Layer 3 VPN multicast support is extended to include PIM dense mode.
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 its 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.