[c-nsp] SP Provider RP in multicast with MPLS/BGP L3 VPN

[Phil Mayers]

Atiqur Rahman Mohammed wrote:
> Can anybody explain why Service Provider rendezvous point (RP) is required
> in multicast Layer 3 VPN environment in addition to VPN RP. It would be
> highly appreciable if anyone points to some good document.

For MVPN, the inner multicast group address (range) is mapped to an 
outer multicast group address (smaller range). Therefore, the outer 
(service provider) network must have working multicast.

If you choose a source-specific-multicast range (recommended) for the SP 
mapping, no RP is required. If you choose an ordinary ASM range for the 
SP mapping, an RP is required as normal for any multicast traffic.

My recommendation (and the examples in most Cisco docs) would be to use 
an SSM range defined out of the local scope.

In fact on a 6500 with SXF2 I had difficultly making MVPN work with ASM.

HTH