Session Date/Time: 28 Jul 2023 19:00

snac

Summary

The SNAC working group met at IETF 117 to discuss the "simple" document, focusing on its readiness for working group last call. Ted presented a detailed review of the document, section by section, highlighting areas needing further work. Discussions covered addressability, prefix delegation, reachability, discoverability, IPv4 support, handling partitioning events, and security considerations. The session also included a presentation by Ted on the experiences of the thread working group in using stub networks, touching on addressability, discoverability, route advertisement and other elements. There were interactions from the attendees of the session.

Key Discussion Points

Document Status: The "simple" document is mostly editorial, but certain sections need more detailed explanations and potentially a state machine for prefix delegation.
Managing Addressability: The organization of the addressability section on the AIL needs improvement and a more prescriptive explanation is needed for the stub network.
ULA Prefix Generation: Concerns were raised about using the Wi-Fi SSID for ULA prefix generation. A preference for using a random number generator and stable storage was expressed.
Prefix Delegation: A state machine is needed for the prefix delegation section. Keeping the OSNR prefix stable and identity association were discussed.
Reachability: Whether to inject only a default route into the stub network versus advertising specific routes was discussed. The consensus was to not over-complicate the "simple" document.
Discoverability: The document needs to be more specific about how to implement service discovery (e.g., SRP, DNS resolver, DNS push).
IPv4 Support: A discussion on the use of NAT64 versus Prefix64 (Pref64) for IPv4 reachability. The group leaned towards requiring Pref64 and exploring the possibility of deprecating support for DNS64.
Security Considerations: Concerns were raised regarding security vulnerabilities from the stub router, and how to protect against attacks. A discussion on best practices, and whether additional security mechanisms should be added.
Thread's experience of Stub Network elements: Presentation that highlighted thread's use of stub networks elements, including some of the practical challenges that have been discovered when deploying stub network elements, such as addressing, dealing with advertisement of routes and discoverability.

Decisions and Action Items

Action Item: Ted and Jonathan (document editors) to address the to-do list items identified during the document review.
Action Item: Explore the possibility of deprecating DNS64 in favor of Pref64.
Action Item: Investigate the security considerations more closely, potentially developing a problem statement for future work.
Action Item: Request early allocation of new router advertisement flag option to indicate stub router prefix
Action Item: The chairs will bring the discussion on the SNAC mailing list on other documents and asking for contributors.

Next Steps

Address the identified to-do items and incorporate feedback from the discussion.
Revisit the working group last call status after addressing the to-do list items.
Continue discussion on the mailing list.