Multicast VPN Extranet
This post talks about how you can do inter-VRF multicast using BGP VPNv4 multicast (SAFI 129).
You might have seen this guide on Cisco.com
Configuring Multicast VPN Extranet Support
They suggest leaking unicast routes between VRFs which isn’t required for this to work.
I’m using this topology to go through the configuration:
Our source is R9 in VRF a which is configured as rosen draft on R10 and R12. The configuration hereof is plain: