Re: [Int-area] [arch-d] Is IPv6 End-to-End? R.I.P. Architecture? (Fwd: Errata #5933 for RFC8200)

[Bernard Aboba <[e-mail]>]

Fernando --

"the proponents have argued that "we have implemented it,
and the industry wants it" -- as if we just have to rubberstamp what
they have done."

[BA] The IETF has no enforcement authority, so that vendors have the
ability to ship products implementing IETF standards in whole or in part -
or not at all.  However, it is within the authority of the IETF to define
requirements, and to articulate the implications of behavior that (some
people) might consider undesirable, so as to provide information so that
customers can make their own decisions.

"Besides, it should be obvious that removal/insertion of EHs en-route
error reporting (since host typically check that the ICMP errors they
receive correspond to something that they actually sent)."

[BA] This is an example of a consequence that should be considered. IMHO,
these issues are worth writing up.

Tom said:

"IMO, what we haven't seen, was a real attempt to resolve and work out the
engineering issues."

[BA] In practice, these kind of issues are rarely "resolved" - points of
contention in "Tussle space" go through cycles of
deployment/analysis/reaction.  So sometimes rather than seeking
"compromise" (which may satisfy noone) it is better to put publish both a
majority and a minority opinion.  This approach not only clarifies the
points of debate, but also puts the positions on record for posterity.

On Thu, Feb 27, 2020 at 1:43 PM Fernando Gont <[e-mail]> wrote:

> Folks,
>
> If you haven't been following recent developments in the Spring WG, you
> may be surprised about some of the work that is being pursued (or was
> being pursued)-
>
> Such work has included proposing that some IPv6 routers insert and
> remove routing headers en-route to the final destination.
>
> After many very heated and lengthy debates, some of this work was
> dropped, but other remains (e.g. routers removing IPv6 EHs from packets
> en-route to their final destination, part of what they call "PSP"). For
> the most part, the proponents have argued that "we have implemented it,
> and the industry wants it" -- as if we just have to rubberstamp what
> they have done.
>
> On the technical side, the proponents have argued that:
>
>      If a packet employs source routing (and hence its Destination
>      Address is modified en-route to direct the packet through each
>      of these "waypoints"), then any of such "waypoint" routers are
>      free to add or remove IPv6 extension headers at will. (No, not
>      encap/decap, but rather add/remove EHs from the IPv6 header
>      chain).
>
> That seems to me like a very major deviation from what's supposed to be
> our current "architecture", where IPv6 is an end to end protocol.
> Besides, it should be obvious that removal/insertion of EHs en-route
> error reporting (since host typically check that the ICMP errors they
> receive correspond to something that they actually sent).
>
>
> A number of us have raised this a number of times, and at least some of
> us feel that our concerns are being ignored.
>
> It would seem to me that these documents and decisions have a concrete
> impact on our architecture, and that they are being pursued without any
> proper oversight. There is also a widespread feeling that having one or
> a few big vendors pushing these ideas might be playing a role here.
>
> (See, for instance:
>
> * https://mailarchive.ietf.org/arch/msg/ipv6/Er7LR_VrsJLko_QnqEKTXvPcpj4/
>
> * https://mailarchive.ietf.org/arch/msg/ipv6/gG7Fbz0R030g55oW1mvckj0THwc/
> )
>
> What I would expect is that all thes major changes to our existing
> architecture and protocols would only done by formally updating existing
> standards *if* deemed appropriate, as opposed to just trying to sneak
> changes "when nobody is watching", or by having very curious
> interpretations of our protocols and standards.
>
> I've raised the topic to our AD (Suresh), to the IAB, and on the arch-d
> list before, but so far haven't been lucky or seen anything meaningful
> happen in this area.
>
> I have also submitted an errata to make RFC8200 even more clear on the
> topic, but it remains unprocessed.
>
> So my questions are:
>
> * On the technical area:
>
>   + Is IPv6 an End To End protocol?  Or is the IETF's stance that
> routers are free to mangle with the packet structure as they please?
>
>   + Was IPv6 designed that way? And if it wasn't, when/how was the
> architecture changed?
>
>
> * On the procedural area:
>
>    + Where/how should IETF WGs seek for architecture-related advice?
>
>    + What do do in situations like the above?  Wait and see how things
>      evolve, and upon any formal decisions, just submit formal Appeals
>      if deemed necessary?  (and after way too much energy consumed from
>      everyone)
>
>      I would have expected that as soon as these issues were raised,
>      the offending text would be removed rightaway. But that wasn't
>      the case. And when the changes did happen, it wasn't without
>      an extraordinary waste of time and energy from all of us.
>      For instance, any work on IPv6 header insertion/deletion wouldn't
>      seem to fit within the charters of the 6man or spring wgs.
>
>
>      FWIW, this is not the first instance of issues surrounding the same
>      topic. It goes back to the rfc2460bis effort, when a similar set of
>      folks (too many from one big vendor) got to have 6man ship
>      what became RFC8200 with a noted "ambiguity", just to be able
>      to have some playground for EH insertion/deletion. And we only got
>      to improve on that during IETF LC:
>
>     (see:
> https://mailarchive.ietf.org/arch/msg/ipv6/Kp76SONpyqWneNgvtc8sh-fGAu0/)
>
>
> Thoughts or advice on the technical and/or procedural aspects will be
> appreciated.
>
> Thanks!
>
> Cheers,
> Fernando
>
>
>
>
> -------- Forwarded Message --------
> Subject: Errata #5933 for RFC8200
> Date: Thu, 27 Feb 2020 17:07:36 -0300
> From: Fernando Gont <[e-mail]>
> To: Suresh Krishnan <[e-mail]>
> CC: [e-mail] <[e-mail]>
>
> Suresh,
>
> Two months ago I filled an errata on RFC8200 regarding the processing of
> IPv6 extension headers. The errata is available here:
> https://www.rfc-editor.org/errata/eid5933
>
> While I believe that folks with a knowledge of Internet Protocols would
> be able to interpret what is in RFC8200, given recent discussions on the
> topic, and upon a re-read of the text, I believe a clarification is
> warranted, such that we allow all sorts of curious interpretations of
> the text.
>
> I send a heads-up on the 6man mailing list
> (https://mailarchive.ietf.org/arch/msg/ipv6/6MPs25WvSMD6vVT0ekaMYjAwM6c/),
>
> and the proposed text received the review of at least Brian Carpenter,
> Ron Bonica, and Mark Smith. Their reviews are available on such thread.
>
> In the light that some folks seem to be pretending to leverage "the lack
> of clarify" in RFC8200 (an Internet Standard) to violate it, I'd
> appreciate that the reported errata be processed.
>
> Processing the aforementioned errata is key to many of the discussions
> this and other WGs are having.
>
> Thanks,
> --
> Fernando Gont
> SI6 Networks
> e-mail: [e-mail]
> PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492
>
>
>
>
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