I have several general questions about Multicast VPN. I have read conflicting information about SSM and the need for RPs within the Service Provider backbone. To my understanding, SSM does not need a RP and per most documents I read, to enable multicast to transverse from CE1 to CE2, on the VRF terminating that customers, I create the MDT utilizing the same group address somewhere in the 18.104.22.168/8 family on both PEs terminating the CEs. On the PEs, in particular the interfaces facing the SP backbone or P routers, I enable sparse-mode on all interfaces throughout the backbone. I also enable ip pim ssm default on all SP devices.
Speaking to the PE side facing the CE, I either turn on sparse-dense mode or possibly define a RP for that VRF using the ip pim vrf X.X.X.X to the customer's RP.
To summarize the steps:
1) define the MDT under the VRF which must match on all PE devices for that VRF
2) enable Sparse Mode on all Service Provider backbone devices
3) enable ip pim ssm default on all SP devices
The questions are, do I need to enable IGMPv3 on all SP backbone links and do I need to create a RP within the SP backbone? Per documentation I have read, a RP is not required with SSM but then again, I have seen some discussions where people were advised to turn up a RP.
This is not a provider to provider situation. This within the same AS.