Subject: [Roll] Heads-up on draft-ietf-6lo-multicast-registration

From: "Pascal Thubert (pthubert)" <[email-masked]>
Date: Wed, 10 Nov 2021 15:48:39 +0000

Dear all:

With draft-ietf-6lo-multicast-registration, 6lo is extending the IPv6 stateful address autoconfiguration (RFC 8505/8928) to express that the node is accepting traffic for an anycast address and to subscribe to multicast addresses.

The model is a proactive push from the device, compared to MLD reports that pulls from the router. There are a number for reasons for doing this that way in energy conscious networks, where multicast and broadcasts are mostly prohibited, and devices sleep most of their time. Also the incremental code on constrained devices that operate IPv6 ND as per RFC 8505 is very minimal.

The proactive model allows the router to inject the MAC and IP information in a network overlay routing or a proxy function in a fashion that is more reliable and economical than the classical snooping of MLD and ND. This is why it is used in RFC 8929 for proxy ND, and proposed for use in RIFT and now eVPN as the IGP-agnostic UNI between the host and the router. 

Since we are extending the registration from unicast to anycast and multicast, Erik and Alvaro suggested that we raise the topic on this list as well. 

I would certainly be happy to help folks are interesting in drafting how subscriptions learned from this new work can be injected in PIM as well.

Keep safe;

Pascal