[lisp] Questions on using LISP's signal free multicast for draft-ghanwani-nvo3-app-mcast-framework

[Linda Dunbar <[e-mail]>]

Dino,

At Toronto NV03 session, you suggested that draft-ghanwani-nvo3-app-mcast-framework can use LISP's signal free multicast scheme.
After studying the draft-farinacci-lisp-signal-free-multicast-00, I agree that the proposed scheme can definitely solve the problem of application initiated multicast in environment where underlay network don't support any IP multicast protocol.

But there are some issues of using the LISP's signal free multicast mechanism in Data Centers when NVEs, especially the server based hypervisor virtual switches,  don't ( or can't) support the "General Receiver-site procedure" documented in the "draft-farinacci-list-signal-free-multicast-00".  The general receiver-site procedure requires egress edge (i.e. egress NVE) to terminate IGMP or PIM messages. But many NVEs (server based virtual switches) don't terminate IGMP nor PIM.

Therefore, NVO3 needs a simpler scheme for "Receiver NVEs".   draft-ghanwani-nvo3-app-mcast-framework-00 suggests all IGMP messages are sent to "multicast server".

Or "Multicast server" can fake "IGMP query" to all the NVEs, which forwarded down to applications. The reply (IGMP report) can be automatically sent back to "multicast server" without NVE doing anything extra.

What do you think?


Linda