Session Date/Time: 27 Jul 2023 20:00

6man

Summary

The 6man working group meeting covered several topics related to IPv6, including updates on existing drafts, discussions on link-local URIs, architecture for IPv6 over non-broadcast access, IOM query mechanisms, extension headers, and individual drafts concerning ULA usage, DHCP prefix delegation, and ICMPv6 flow block masks. Several drafts were proposed for adoption and the working group is seeking feedback to advance document maturity.

Key Discussion Points

Link-Local URIs: The discussion focused on resolving discuss ballots, particularly concerning W3C objections to ABNF changes for URL syntax. Use cases for link-local URIs were discussed, including marine networking (NEMA), server interface specification, and potential integration with DNS resolvers. Concerns regarding interface name ambiguity and TLS handling were raised.
Architecture for IPv6 over Non-Broadcast Access (NVMA): The presentation covered definitions of key terms like "interface," "link," and "subnet." The document's applicability to various network types, including Wi-Fi (802.11) and EVPN overlays, was discussed. The definition of the "subnet gateway protocol" was highlighted. Concern was raised that multicast was not well-addressed and that the architecture may add unneeded complexity to general purpose links.
IPv6 IOM Query: The presentation updated the group on the progress of the IOM draft, including the removal of the ILN incremental tracing capability object, the addition of new examples of IOM information query, and clarifications regarding ECMP scenarios. There was discussion on whether the document should be experimental or standard track, as well as security considerations (amplification attacks).
IPv6 Hop-by-Hop Options Processing: The presentation reviewed changes made to the hop-by-hop options processing document since the last working group last call and a summary of the updates to RFC 82100 was presented. Concerns were raised regarding the possibility of hop-by-hop option filtering at domain edge points. The group discussed the degree to which one could rely on new hop-by-hop options.
ULA Usage: The proposal aims to demote IPv4 further down, simplifying migration to IPv6-only networks. The key changes proposed were (1) to alter the default policy table to elevate the precedence of ULA prefixes over IPv4, and (2) to encourage greater configurability of preference rules. Whether to mandate or recommend configurability was discussed and it was argued for it being only recommended and not required. The group discussed the problems in the current RFC 6724 and expressed urgency to get defaults fixed.
DHCP Prefix Delegation Signaling: The presentation introduced a mechanism for the network to signal to the device whether to attempt to get a prefix for a prefix delegation. There was discussion about the dynamic switching between DHCP and Slack based on PD failures and how to propagate these flags in different networking scenarios.
ICMP loopback extension header A draft was presented on the ICMP loopback extension header for monitoring data paths end-to-end. There were comments on amplification attacks and existing data collection mechanism IOM.

Decisions and Action Items

Link-Local URIs: Eric to close discuss points and work with ISG members.
Architecture for IPv6 over Non-Broadcast Access (NVMA): Pascal to address the concerns about multicast. Discussions to continue on the mailing list.
IPv6 IOM Query: Authors to consider adding a security consideration section addressing amplification attacks. Also, re-evaluate which RFCs are being updated.
IPv6 Hop-by-Hop Options Processing: Authors to address the feedback in the queue, especially regarding BCP 14 language and terminology. Plan to do a revised version, and then another working group last call.
ULA Usage: The authors will work to reword configurability of preference rules as recommended but not required.
DHCP Prefix Delegation Signaling: Discussions to continue on the list.

Next Steps

The working group will continue to review and discuss the presented drafts on the mailing list.
Authors will revise drafts based on feedback received during the meeting.
A new working group last call might be issued for updated drafts.
The chair will coordinate adoption calls for drafts that are deemed ready.