There are clearly technical issues with this document (cfr the 2 DISCUSS at the IESG ballot and my own AD review who pointed to this problem and warned that the IESG may block it).
The situation is sad indeed, but, as the responsible AD, I am sending this draft back to the WG as it is *not* ready for publication. I also suggest the intarea WG chairs to check whether there is a consensus to continue working on this I-D knowing that other ICMP-related documents are mostly ready for publication. Thanks for all the work done in this draft, there was indeed an oversight in RFC 8335 :( Regards -éric From: Bob Hinden <[email protected]> Date: Sunday, 19 October 2025 at 07:05 To: Xiaoming He <[email protected]> Cc: [email protected] <[email protected]>, 【外部账号】 <[email protected]>, Gorry Fairhurst <[email protected]>, Ketan Talaulikar <[email protected]>, hexm4 <[email protected]> Subject: [Int-area] Re: Status of draft-ietf-intarea-icmp-exten-hdr-len-02 Xiaoming, On Oct 18, 2025, at 9:10 PM, Xiaoming He <[email protected]> wrote: Hi，Bob, We have a consensus about defining the length field in the Extension Header among the authors. One of the authors (Ron Bonica) said "I believe that this draft should be withdrawn”. How is that a consensus? We believe that this draft can help address the issues mentioned in previous eamil. I also believe that this draft is ready for publication. There are also two IESG DISCUSS votes that have not been cleared. I don’t see how you can say the draft is ready for publication. Perhaps I am confused. Please explain. Bob Best Regards, Xiaoming 原始邮件 ________________________________ 发件人：Bob Hinden <[email protected]> 发件时间：2025年10月18日 23:25 收件人：[email protected] <[email protected]> 抄送：【外部账号】 <[email protected]>, Gorry Fairhurst <[email protected]>, Ketan Talaulikar <[email protected]>, hexm4 <[email protected]> 主题：[Int-area] Re: Status of draft-ietf-intarea-icmp-exten-hdr-len-02 Hi, Speaking as an Int Area participant, given the IESG DISCUSS comments and that the authors appear to disagree, I think this should be sent back to the working group. Given the lack of WWW among the authors, I conclude it should no longer be a w.g. draft. The authors can, of course, continue working on the draft to resolve the issues. Bob On Oct 17, 2025, at 11:01 PM, [email protected] wrote: Hi, Ron and Eric, I have the different opinions. I believe that this draft should be expected to solve two issues.. The first issue is obvious. According to RFC4884, the Extension Structure contains exactly one Extension Header followed by one or more objects. Actually, there may exist more objects containd by one Extension Header, as described in the previous versions of draft-ietf-6man-icmpv6-reflection-11. If there is no length field in the Extension Header, it will be difficult for the receiver to parse these objects (except for assuming one object). The second issue is that the Extension Structure must be appended to the end of an ICMP message according to RFC4884, if and only if this ICMP message has the reserved space for a length attribute representing the length of the "original datagram" (optional data) field. However, the following ICMP messages are not extensible as currently defined, because these messages lack spaces for a length attribute.: - ICMPv4 Destination Unreachable - ICMPv4 Time Exceeded - ICMPv4 Parameter Problem -ICMPv4 Echo Request/Reply - ICMPv6 Destination Unreachable - ICMPv6 Packet Too Big - ICMPv6 Time Exceeded - ICMPv6 Parameter Problem -ICMPv6 Echo Request/Reply If a length field is added to the ICMP Extension Header, the above-mentioned ICMP messages can be extensible by inserting an extension structure before the original datagram or the optional data field. As decribed in draft-ietf-intarea-rfc8335bis-01, the main difference between this darft and RFC8335 is that the optional data field is appended to the Extension Structure. The length field in the Extension Header can help to determine the offset of the optional data field even if the Extension Header contains more objects. Best Regards, Xiaoming ________________________________ [email protected] From: 【外部账号】Ron Bonica<mailto:[email protected]> Date: 2025-10-18 10:18 To: Eric Vyncke (evyncke)<mailto:[email protected]>; [email protected]<mailto:[email protected]> CC: [email protected]<mailto:[email protected]>; xiao.min2<mailto:[email protected]>; Tal Mizrahi<mailto:[email protected]>; Gorry Fairhurst<mailto:[email protected]>; Ketan Talaulikar<mailto:[email protected]> Subject: Re: Status of draft-ietf-intarea-icmp-exten-hdr-len-02 Hi Eric, I believe that this draft should be withdrawn. Initially, the draft had the following goals: 1. To correct an oversight in RFC 4884. 2. To rescue the ICMP Extended Echo Request/Reply from misuse. While the first goal is laudable, it isn't worth the effort. Generally speaking, a variable length data structure should include a length attribute. If it doesn't, its length must be inferred. While various techniques allow us to infer length, each technique introduces its unique drawbacks. As Ketan points out, the second goal is not attainable. Currently, ICMP implementations infer extension structure length by subtracting the extension structure offset from the total length of the ICMP message. This works, so long as the extension structure is the last item in the ICMP message. Some years ago, RFC 8335 implementations added information to the ICMP Extended Echo Request/Reply messages. Rather than encoding this information in the extension structure, they encoded it after the extension structure. So, in the Extended Echo Request/Reply messages, we can no longer infer the extension structure length using the old technique. We must assume that in ICMP Extended Echo Request/Reply messages, the extension structure contains exactly one object. So, its length can be calculated by adding the extension header length to the length of the one and only object. We would not have had this problem if the Extended Echo Request/Reply had a length attribute on day one. However, it's too late to rescue the ICMP Extended Echo Request/Reply messages by adding one. The only way to maintain backwards compatibility with legacy PROBE implementations is to limit the number of objects that the extension structure can carry in the Extended Echo Request/Reply. Ron Juniper Business Use Only ________________________________ From: Eric Vyncke (evyncke) <[email protected]> Sent: Friday, October 17, 2025 4:48 AM To: [email protected] <[email protected]> Cc: Ron Bonica <[email protected]>; [email protected] <[email protected]>; xiao.min2 <[email protected]>; Tal Mizrahi <[email protected]>; Gorry Fairhurst <[email protected]>; Ketan Talaulikar <[email protected]> Subject: Status of draft-ietf-intarea-icmp-exten-hdr-len-02 [External Email. Be cautious of content] Dear authors, dear intarea WG, It seems that this I-D has reached a dead-end based on all email discussions after the IESG evaluation and the blocking DISCUSS ballot by Gorry and Ketan (in cc). I sincerely think that this I-D should be removed and not published anymore, especially in the light of draft-ietf-intarea-rfc8335bis, which is in WG Last Call. What do you and the intarea WG think about this removal ? Regards -éric (after discussion with the intarea WG chairs) _______________________________________________ Int-area mailing list -- [email protected] To unsubscribe send an email to [email protected]
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