Session Date/Time: 10 Nov 2023 08:30

snac

Summary

This meeting focused on advancing the SNAC specification through collaborative editing and issue resolution. Key topics included defining "suitable" prefixes, relaxing requirements for single ULA prefixes, handling RA header parameters, and considering prefix delegation behaviors. Participants actively contributed to text editing and discussed various scenarios, including misconfigurations in home networks and interactions with RA guard. The group agreed to address ambiguities in RFC 8415 regarding prefix delegation and encouraged collaboration for future implementation and interoperability testing.

Key Discussion Points

Suitable Prefix Definition: Extensive discussion on the term "usable prefix" and its potential for misinterpretation. Agreement to define the term "suitable prefix" explicitly in the terminology section.
Single ULA Prefix Requirement: Examination of the requirement for a single ULA prefix, considering scenarios with multiple prefixes for the AIL and stub networks. Agreement to relax the "must" to a "should" and clarify text related to the ULA usage.
RA Header Parameter Handling: Discussion on the importance of copying RA header parameters, specifically the M and O flags, from infrastructure RAs to avoid confusing hosts. The group considered scenarios with conflicting RAs and the need to handle stub router RAs differently. A new section on constructing RAs was proposed.
RFC 4191 Host Types: Discussion on the relevance of host types (A, B, and C) defined in RFC 4191, particularly in the context of subnetworks. Agreement that type A and B hosts are effectively unsupported and text explaining why should be included in the specification.
Prefix Delegation (PD) Behavior: Concerns raised regarding the lack of clarity in RFC 8415 regarding PD client behavior, particularly in change situations. Agreement that Esco will review RFC 8415 and raise issues in the DHCP working group.
PD per Device: Explored the applicability of Prefix Delegation per device, acknowledging host behavior as out of scope for the current document. The possibility of releasing prefixes and the related issues with DHCP-provided prefixes were discussed.

Decisions and Action Items

Define "Suitable Prefix": Ted to define "suitable prefix" in the terminology section of the document.
Relax Single ULA Prefix Requirement: Jonathan and Ted to relax the “must” requirement for a single ULA prefix in section 5.2.2 and adjust surrounding text, separating use cases for generation and use of ULA prefix.
RA Construction Section: Jonathan and Ted to create a new section on constructing RAs, including considerations for different network types and handling conflicting RA parameters.
Address Host Type Compatibility: Jonathan and Ted to add text explaining the incompatibility of RFC 4191 type A and B hosts with subnetworks and why this is considered an acceptable failure mode.
Review RFC 8415: Esco to review RFC 8415 and raise concerns about ambiguities in prefix delegation behavior with the DHCP working group.
Promote PD in Home Gateways: Work with matter folks to recommend that home gateways do PD.

Next Steps

Jonathan and Ted to incorporate the discussed changes into the document.
Esco to review RFC 8415 and report back to the working group.
Working group members to provide feedback on the updated document and propose text edits using the specified bracketed format.
Investigate collaboration with Tim on his DHCP draft and coordinate with matter to encourage home gateways to support releases and relevant functionality.
Consider a hackathon in Brisbane to promote implementation and interoperability testing.