Re: about violation of standards

[Alexandre Petrescu <[e-mail]>]

Le 18/04/2019 à 21:53, Kerry Lynn a écrit :
> On Thu, Apr 18, 2019 at 3:30 PM Kerry Lynn <[e-mail] 
> <mailto:[e-mail]>> wrote:
> 
>     On Thu, Apr 18, 2019 at 2:59 PM Alexandre Petrescu
>     <[e-mail] <mailto:[e-mail]>>
>     wrote:
> 
>         In private conversation this debate happened:
> 
>         is an implementation that uses fe80:1::2 address on an interface a
>         violation of standards? (RFC 4291 does not allow for '1' to be
>         there).
> 
>         My point of view is that as long as that mplementation is widely
>         used,
>         that is not a violation of standards.  Rather, the situation
>         makes it
>         that that standard is not in agreement with implementations.
> 
>         Alex
> 
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> 
>     Which came first, the standard or the egg?
> 
>     Kerry
> 
> 
> Let me expand on my answer, which was (perhaps) pithy but not very helpful.
> I don't believe, in general, that standards are created in a vacuum or 
> for no
> purpose.  Particularly when one is working in very constrained environments,
> it is often the case that violating one constraint may have knock-on 
> effects.
> 
> In the case of 6LoWPAN HC1 compression, it is assumed the 54 bits following
> fe80::/10 are zero, which, in turn, allows the lower 64 bits of the IPv6 
> address to
> be elided for all 6lo data links that I'm familiar with.
> 
> I suppose one could argue that for link-local traffic, all the nodes 
> could agree
> that fe80:1::/64 is the local convention, but 1) don't then claim 
> conformance with
> HC1 header compression and 2) prepare to write your own sniffer.

Thank you for the suggestion.

In another foo (not 6LoWPAN) some nodes agree with fe80:1::.  This does 
not disturb 6lowpan links.

In this sense, I think it can not be said that fe80:1::/32 violates 
anything in 6lowpan.

This is why I do not understand the suggestion.

Alex

> 
> Kerry