Inter-AS Option C is supported for Rosen MVPN PIM SSM using BGP MDT SAFI and PIM RPF Vector. Figure 1 depicts a default MDT setup:
Additional caveats for Inter-AS MVPN Option B and C support are the following:
Inter-AS MVPN Option B is not supported with duplicate PE addresses.
For Inter-AS Option C, BGP 3107 routes are installed into unicast rtm (rtable-u), unless routes are installed by some other means into multicast rtm (rtable-m), and Option C will not build core MDTs, therefore, rpf-table is configured to rtable-u or both.
Additional Cisco interoperability notes are the following:
RFC 5384 - the Protocol Independent Multicast (PIM) Join Attribute Format
RFC 5496 - the Reverse Path Forwarding (RPF) Vector TLV
RFC 6513 - multicast in MPLS/BGP IP VPNs
The SR OS implementation was designed to inter-operate with Cisco routers Inter-AS implementations that do not comply with the RFC5384 and RFC5496.
When configure router pim rpfv mvpn option is enabled, Cisco routers need to be configured to include RD in an RPF vector using the following command: ip multicast vrf vrf-name rpf proxy rd vector for interoperability. When Cisco routers are not configured to include RD in an RPF vector, operator should configure SR OS router (if supported) using configure router pim rpfv core mvpn: PIM joins received can be a mix of core and mvpn RPF vectors.