Session Date/Time: 22 Jul 2025 12:30

pim

Summary

This PIM working group meeting covered several key topics, including updates on RFC publications, ongoing draft revisions, and discussions on new problem statements and solutions. Key discussions revolved around host requirements for multicast, PFM forwarding enhancements, dynamic multicast address assignment, backup DR election, and multipath support for IGMP/MLD proxy. Several drafts are nearing working group last call.

Key Discussion Points

IGMPv3 and MLDv2 Updates: Discussion of the recent publication of RFCs related to IGMPv3 and MLDv2, and the effort to bring them to full standard status.
Host Requirements for Multicast: Torles discussed updates to the host requirements draft, focusing on the necessity of multicast support in IPv4 and IPv6, and the implications for IGMP and MLD. Emphasis on supporting link-local scope multicast without IGMP/MLD if necessary.
PFM Forwarding Enhancements: Frank presented on enhancements to PFM, including the addition of sub-TLVs for more flexible data transmission and optimizations for message forwarding over multiple links.
Dynamic Multicast Address Assignment: Nate discussed the problem statement for dynamic multicast address assignment in marine networks and presented two proposed solutions: a zero-conf solution based on MDNS and a new protocol called GAAP. Addressed concerns about address collisions and security considerations. Stig requested a comparison of the two solutions in the draft.
PIM Backup DR: Manav discussed PIM backup DR and delayed DR election mechanisms. Discussion of whether to adopt with sticky DR or without, and the issue of traffic loss during DR re-election. Comparison of delaying and setting up a BDR.
Multipath Support for IGMP/MLD Proxy: Yisong presented on multipath support for IGMP/MLD proxy and proposed merging the signaling draft with the static configuration working group draft.
LISP Joint Prune Attribute Bis: Evan and Stig discussed obsoleting the two experimental RFCs to move them to standard track, also discussing a potential issue with IANA code points.
Stateless Multicast Forwarding in PIM: Discussion with Greg about moving a BEER solution to PIM, with Greg being opposed, and presenting a stateless alternative.
IP RPF Vector Conflict Resolution: Yisung presented a draft on IP RPF vector conflict resolution, with participants highlighting the need for more brainstorming on the solution and its potential impacts on existing implementations.

Decisions and Action Items

Host Requirements Draft: Initiate working group last call for the host requirements draft.
Dynamic Multicast Address Assignment: Move the problem statement, zero confis assignment, and GAAP drafts to working group last call.
Dynamic Multicast Address Assignment: Nate to add more text comparing and contrasting the two solutions and their use cases to the drafts.
LISP Joint Prune Attribute Bis: Evan to update the draft to indicate obsoleting, rather than updating, and to check IANA code points.
Multipath Support for IGMP/MLD Proxy: Determine on the mailing list whether to merge the signaling draft with the static configuration working group draft.
PIM Backup DR: Get feedback on BDR and potentially include a longer slot at a future meeting to discuss pro's and con's of the solutions.

Next Steps

Working group last calls will be initiated for drafts that are ready.
Discussions will continue on the mailing list for open issues and draft revisions.
A longer slot will be reserved at the next IETF meeting for in-depth discussion of the PIM backup DR draft.