Session Date/Time: 07 Nov 2025 14:30

6MAN

Summary

The 6MAN working group meeting covered a tight agenda, addressing the status of several working group documents, discussing new proposals, and deliberating on the future direction of ongoing work. Key discussions included the disposition of the extension-header-limits draft, necessary updates to the IPv6 Node Requirements document, and initial feedback on new proposals for network resource partitioning, sub-link scope multicast, SRv6 error handling, and DNS64 advertisement. Authors of less-than-link-scope-multicast and crh-helper requested adoption calls.

Key Discussion Points

Administrative Items:
- Chairs (Bob Hinden, Jen Linkova) welcomed attendees and reminded everyone of the Notewell, Meetecho usage, minute taking (Lou Berger), and IETF network status.
Document Status Updates:
- RFCs Published: Three RFCs have been published since the last meeting.
- Documents in MISREF:
  - Two documents are in MISREF due to dependencies on the SNAC Simple draft.
  - draft-ietf-6man-icmpv6-reflection-filter is in IESG review but is blocked by lack of support for 8335bis during its working group last call in the Internet Area. Bill Fenner encouraged review of 8335bis.
- 6724bis Discussion: A discussion was held regarding potential updates to RFC 6724 related to Happy Eyeballs behavior, specifically around preferring native IP over synthesized Net64 or CLAT addresses. Lorenzo Colitti indicated he would draft text describing the desired behavior to inform potential updates to RFC 6724.
- draft-ietf-6man-extension-header-limits:
  - This document received five IESG DISCUSSes and was returned to 6MAN due to lack of consensus on its content within the IESG review.
  - Chairs concluded there was no working group consensus on the document's content, and it has been released as an individual Internet-Draft.
  - Elliot Lear (Independent Submissions Editor) stated that he would not accept it as an independent submission, citing updates to RFCs 8504 and 8200 and the prior IESG DISCUSSes.
  - Participants suggested that future work on this problem should take a different approach, potentially breaking it into smaller documents (e.g., host-side vs. router-side) and focusing on protections from excessive hop-by-hop options, rather than setting minimums that might ossify into maximums.
- draft-ietf-6man-slack-renaming: Currently in working group last call, pending confirmation that previously raised concerns have been addressed.
ICANN TLD Address Proposal:
- Warren Kumari sent an email to the list regarding an ICANN proposal to reserve special IPv4 and IPv6 addresses for TLDs used internally but not publicly registered.
- Georgios Z. agreed to work on a draft for INTAREA, as the issue spans both IPv4 and IPv6.
draft-shirasaki-6man-srh-comp-sid-8754-update (SRH Compression Update):
- Sreeraman Rajan presented on updates to RFC 8754 (SRv6 Network Programming) to align with spring's Compressed SID document (CSID).
- The draft clarifies that the IPv6 destination address is derived by applying a function (e.g., expansion) rather than direct copying from the SRH.
- The chairs requested wider review of the draft.
draft-ietf-6man-nrp-ipv6-eh (NRP Network Resource Information in IPv6 Extension Header):
- Ji Dong presented an update, aligning terminology and design principles with T's Working Group conclusions, now using "NRP selector ID".
- A key discussion point was the length of the NRP selector ID (variable vs. fixed, 32-bit vs. shorter) and the need for a "context" field.
- Sreeraman Rajan and Pascal Thubert voiced preference for a fixed-length ID for hardware efficiency and questioned the need for a generic context if the primary use case is slicing.
- Charlie Telecom expressed support for a 32-bit fixed length for long-term extensibility.
- Decision: Further discussion on NRP selector ID length and context will be taken to the mailing list.
draft-ietf-6man-ipv6-nd-yang (IPv6 Neighbor Discovery Yang Model):
- Fan Jiang presented an update. The document defines a YANG model for IPv6 Neighbor Discovery and related functions not covered by existing IETF YANG models.
- It was originally an RTGWG document but has been re-adopted by 6MAN.
- Chairs requested operators and implementers to review the draft and provide feedback.
draft-ietf-6man-ipv6-iom-query (IPv6 IOM Capabilities Query):
- Xiaoming Li presented this companion document to ARC IT359, defining ICMPv6 extensions for In-situ OAM (IOM) capabilities discovery.
- The author requested a working group last call.
- Chairs noted that the document needs more review from people familiar with the problem space before advancing.
draft-ietf-6man-node-requirements (IPv6 Node Requirements):
- Tim Chown presented updates, including:
  - Mandatory hop-by-hop option processing for 802.8 and less constrained devices.
  - "SHOULD" for PD-DHEPV6 (RFC 9663) for prefix allocation to hosts and discovery of IPv6 prefixes for address synthesis.
  - "SHOULD" for PCP.
  - Discussion on changing DHEPV4 option 108 (IPv6-only host) from "MAY" to "SHOULD". Lorenzo Colitti questioned potential conflicts with V6OPS recommendations for mobile vs. non-mobile hosts.
  - Informational text added for extension header visibility (RFC 9726) and IPv4-mapped DNS entries.
- Extension Header Limits Text: The author brought up the existing text in RFC 8504 (which node-requirements aims to update) regarding extension header limits. There was a strong sense from the room (Lorenzo Colitti, Jen Linkova) that this text should be removed from node-requirements to allow the document to progress, and the broader extension header limits problem should be addressed separately by the working group.
- Decision: The authors will remove the extension header limits text from draft-ietf-6man-node-requirements.
- Remaining updates include referencing RFC 6724 for default address selection, DHEPV6 for internet standard, and CE Router once they finish their process.
- Consideration of adding P-flag support (RFC 9762) as a node requirement.
- The authors aim for a working group last call after the next IETF meeting.
draft-dvassallo-6man-less-than-link-scope-multicast (Less Than Link Scope Multicast):
- David Vassallo presented a new IPv6 multicast address format for scopes less than the entire link, designed to map to specific Ethernet group ranges (e.g., 01-80-C2-00-00-0E-10 for LLDP).
- The goal is to allow IPv6 protocols to utilize the same sub-link layer 2 propagation characteristics as LLDP (e.g., not crossing switches/bridges), useful for EVPN, security, and layer 3 visibility of layer 2 hops.
- Michael Richardson (ANIMA, GRASP) expressed strong support for the proposal. Eric Klein found it interesting and worth pursuing.
- Action Item: The chairs will initiate an adoption call for this draft on the mailing list.
draft-bonica-6man-crh-helper (CRH Helper):
- Ron Bonica presented an experimental IPv6 destination option, the CRH Helper, designed to precede a Compact Routing Header (CRH).
- It carries prefix information to convert CIDs in the CRH to IPv6 addresses, removing the need for CRH Fibs and routing protocols for prefix maintenance in limited domains (e.g., underlays using small subnets like /112 or /96).
- It is functionally similar to the deprecated RH0 but is shorter and intended for limited domains with security considerations relying on ACLs.
- The author requested a call for adoption, noting the experimental nature and defined success criteria.
- Action Item: The chairs will initiate an adoption call for this draft on the mailing list.
draft-liu-6man-dns64-adv (DNS64 Functionality Advertisement for DNSRI Option):
- Tran Ho presented a proposal to introduce a T-flag in the DNSRI option to signal the presence of DNS64 server addresses.
- The intent is to allow IPv6-only users to get DNS64 addresses while dual-stack users get dual-stack configurations.
- Significant concerns were raised by Jari Arkko, Ted Lemon, and Lorenzo Colitti regarding the necessity of the proposal:
  - Existing mechanisms (host-based address synthesis, Pref64 option) already address the problem.
  - Operational complexity of deploying new RA options.
  - The trend in IETF is towards host-based synthesis, making this proposal seem to move in the opposite direction.
  - The use case was not clearly understood by many in the room.
- Decision: The authors were encouraged to clarify the problem statement and rationale, considering existing solutions and deployment realities.

Decisions and Action Items

6724bis / Happy Eyeballs: Lorenzo Colitti will draft text describing desired Happy Eyeballs behavior for discussion.
draft-ietf-6man-node-requirements: The working group (by sense of those present) has decided to remove the extension header limits text from this document to allow its progression.
draft-ietf-6man-nrp-ipv6-eh: Discussion on the NRP Selector ID length and context will continue on the mailing list.
draft-dvassallo-6man-less-than-link-scope-multicast: Chairs will initiate an adoption call on the mailing list.
draft-bonica-6man-crh-helper: Chairs will initiate an adoption call on the mailing list.
draft-liu-6man-dns64-adv: Authors are requested to clarify the problem statement and justify the need for a new mechanism given existing solutions and operational concerns.
Cross-WG Drafts: For drafts touching other WGs, authors should ensure the other WG chairs explicitly request or adopt the work.
ICANN TLD Addresses: Georgios Z. will work on a draft for the INTAREA.

Next Steps

Continue mailing list discussions on draft-ietf-6man-nrp-ipv6-eh.
Chairs will follow up with Spring WG chairs regarding draft-ali-6man-srv6-handling-time-to-exceed.
draft-ietf-6man-node-requirements will be updated to reflect decisions, with an aim for WGLC possibly before or after the next IETF.
Working group members are encouraged to review open drafts, particularly draft-shirasaki-6man-srh-comp-sid-8754-update, draft-ietf-6man-ipv6-nd-yang, and draft-ietf-6man-ipv6-iom-query, and provide feedback on the mailing list.
Chairs will gauge interest for adoption calls for draft-dvassallo-6man-less-than-link-scope-multicast and draft-bonica-6man-crh-helper.