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

[Fernando Gont <[e-mail]>]

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]
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