Re: draft-bourbaki-6man-classless-ipv6-00

[Brian E Carpenter <[e-mail]>]

On 07/06/2017 13:14, 神明達哉 wrote:
> At Tue, 06 Jun 2017 23:30:30 +0000,
> Job Snijders <[e-mail]> wrote:
> 
>>>>> But that is exactly what the draft does *not* do. Nobody would
>>>>> change a single instruction in existing code as a result of this
>>>>> draft. (I agree with you that some O/S stacks may need fixing, but
>>>>> they already need fixing.)
>>>>
>>>> is this draft exactly:
>>>>
>>>>    IPv6 unicast routing is based on prefixes of any valid length up to
>>>>    128 [BCP198].  Interface Identifiers should be 64 bit long except
>>>>    when the addresses are manually configured, or by exceptions defined
>>>>    in standards track documents.  For example, [RFC6164] standardises
>>>>    127 bit prefixes on inter-router point-to-point links.  The rationale
>>>>    for using 64 bit Interface Identifiers can be found in [RFC7421]
>>>>
>>>> ?
>>>
>>> Yes. Put those words in 4291bis and I will be very happy. Oh ;-).
>>
>> I recall a small but vocal group arguing fiercely against that text
>> adjustment, so here we are.
> 
> As several people including myself have already pointed out, it's very
> hard for ordinary readers to understand that's really what
> draft-bourbaki-6man-classless-ipv6-00 tries to propose.  It will have
> to be heavily revised to convey that message.
> 
> As for the above text, my recollection is that some people (I don't
> know if that was a small group, btw - to me both groups looked equally
> vocal and equally small/large) were against one specific point in
> text like the above one:
> 
> - "should be 64" instead of "must be 64" (but in my understanding they
>   were/are okay with "except when the addresses are manually
>   configured")
> 
> It's also not clear to me whether the real intent of
> draft-bourbaki-6man-classless-ipv6-00 includes the subtle (but
> seemingly very important for those who were "fiercely against" it)
> change from "must" to "should".  I guess if the authors of
> 6man-classless-ipv6 are actually also happy/okay with this one:
> 
>     IPv6 unicast routing is based on prefixes of any valid length up to
>     128 [BCP198].  Interface Identifiers must be 64 bit long except
>     when the addresses are manually configured, or by exceptions defined
>     in standards track documents.  For example, [RFC6164] standardises
>     127 bit prefixes on inter-router point-to-point links.  The rationale
>     for using 64 bit Interface Identifiers can be found in [RFC7421]

Speaking for myself only, yes, happy.

   Brian

> 
> then there will be no dispute or further time wasting (we'll still
> need to decide what to do with the magic leading bits of 000 in terms
> of the interface identifier length, but if we can agree at this level
> this will be a relatively minor point to address).
> 
> --
> JINMEI, Tatuya
>