Session Date/Time: 08 Nov 2023 13:30

6man

Summary

The 6man meeting covered several active working group and individual drafts related to IPv6. Discussions included the status of RFC 6874 bis and segment identifiers, updates on the extension header limits draft, adoption call for the CRH draft, and the handling of expired working group documents. Presentations and discussions were held on limiting extension headers, enabling IOM capabilities discovery, updating RFC 6724, enabling PD per device, and in-flight removal of IPv6 options.

Key Discussion Points

Extension Header Limits: A key point of discussion revolved around the proposed 64-byte default limit for extension headers and whether this limit, if enshrined in a BCP, would be too restrictive and prevent the use of extension headers for certain applications. The discussion touched on the trade-off between a practical limit based on current router capabilities and a more extensible limit. Alternative proposals included a "should support more" recommendation, or defining a minimum floor. There was discussion on making sure the limit is applicable only when sending to the open Internet. Concerns were raised that a 64-byte limit might preclude RFCs that already require more than 64 bytes.
RFC 6724 Update: The primary motivation for the RFC 6724 update is to improve the preference for ULAs over IPv4 addresses within a local network. The discussion highlighted the issue of streamlining the draft, clarifying its intent, emphasizing ULA-to-ULA preference, clarifying the interaction with globally routable addresses, and strengthening the text regarding rule 5.5.
PD per Device (DHCPv6 Prefix Delegation): The discussion concerned adding a flag to the PIO (Prefix Information Option) to indicate that the prefix should not be used for SLAAC, but rather for PD (Prefix Delegation). Questions arose concerning whether the flag should be a global flag for the RA or a prefix-specific flag in the PIO, and the interaction with the "L" (on-link) flag.
NPTv6: Moving NPTv6 to a standards track caused some debate, especially regarding government requirements and concern with its implementation. It was also suggested that effort should be put towards Multi-homing solutions with PA space.

Decisions and Action Items

Extension Header Limits:
- Tom Herbert will create a new revision based on the chair's comments.
- Two working group members will perform a detailed review of the document.
- Determine if the limit is only for packets sent on the public internet.
RFC 6724 Update:
- New revision needed to make clear that preference is for ULA to ULA and provide an implementation section.
- Ask on the list regarding rule 5.5 being a "must".
PD per Device:
- Ask on the list regarding if the hosts should really disregard SLAAC.
- A poll will confirm whether this is a viable mechanism or not.
NPTv6: A poll was created to confirm the implementation. Results will be taken to the list.

Next Steps

Tom Herbert to update the extension header limits draft based on chair's feedback and solicit additional reviews.
Authors of the RFC 6724 update to create a new revision, incorporate feedback, and seek clarification on "must" vs "should" regarding rule 5.5.
Discuss adoption call on the mailing list.
Authors of the PD per device draft to address comments on the mailing list.
Discuss NPTv6 on the mailing list.