Re: [IPv6] I-D Action: draft-ietf-6man-eh-limits-02.txt

[Bob Hinden <[e-mail]>]

Ole,

> On Mar 2, 2023, at 7:58 AM, Ole Troan <otroan=[e-mail]> wrote:
> 
> Tom,
> 
>> It's a classic "chicken and egg problem". Extension headers would on
>> be deployable if there are real use cases, but we can't develop real
>> use cases unless they are deployable.
> 
> There might be an aspect of that, but I don’t think that’s the whole truth.
> It is quite telling that there isn’t a single universally “interesting” extension header.

I continue to think that RFC9268 "IPv6 Minimum Path MTU Hop-by-Hop Option” is both interesting.

Bob


> That’s applicable to intermediate nodes. You could almost generalise it to any node.
> 
>>> As an implementor I am quite unhappy when headers aren’t at fixed and predictable offsets in the packet.
>> 
>> As an implementer I am quite unhappy that some vendors and operators
>> have taken arbitrary liberty to block protocols thereby ossifying the
>> Internet and otherwise make protocol conformance optional for the
>> purposes of their financial gain. The effect is that we need to
>> reverse engineer these implementations and policies to provide
>> workarounds to continue to give end users the best service and the
>> benefits of an evolving Internet.
>> 
>> In any case, the problems and perceptions about extension headers have
>> been well documented. Now the question is: what is IETF going to do
>> about it? This draft and hbh-processing are attempting to address at
>> least part of the problem.
> 
> It’s not like there is a raft of use cases / solutions waiting for extension headers to magically start working.
> I’ve come to the conclusion that it’s just the wrong layer. 3.5 isn’t a layer. ;-)
> Limited domains, sure, there’s some special cases there. Although they could also be resolved by TLVs in tunnel headers.
> 
> But I’m not going to stop anyone who thinks spending effort on EHs is useful.
> 
> Best regards,
> Ole
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