Re: RFC4291bis

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

On 09/08/2018 06:43, 神明達哉 wrote:
> At Wed, 8 Aug 2018 11:39:23 +1200,
> Brian E Carpenter <[e-mail]> wrote:
> 
>> Assuming that we adopt draft-farmer-6man-exceptions-64
>> for the standards track or BCP, I suggest that we should
>> also update draft-ietf-6man-rfc4291bis as proposed below,
>> and plan for the two documents to be published as RFCs
>> simultaneously:
> 
> I don't see how we can suddenly agree on publishing rfc4291bis as an
> IS with keeping the most controversial text just with some new wording
> tweak and a reference to draft-farmer-6man-exceptions.  In fact, if it
> were possible, I suspect we could even do that without a new document
> (i.e., 6man-exceptions).

I don't think it's "suddenly". If we can reach agreement on the
way draft-farmer describes things, then we can simultaneously use that
to reach rough consensus on 4291bis. The two things go together.

   Brian

> 
> To this end I wondered how we failed with
> draft-ietf-6man-rfc4291bis-09 and have skimmed the discussion at that
> time starting from:
> https://www.ietf.org/mail-archive/web/ipv6/current/msg27919.html
> and found the following controversial points:
> 
> - the word "by exceptions defined in standards track documents" (see
>   also my recent message to the draft-farmer-6man-exceptions thread)
> - referring to a specific way of configuring addresses (in particular
>   SLAAC) from the Addressing *Architecture* document.
> 
> The proposed new text still has these two points.  I'd be pessimistic
> about the odds for "this time is different" just because of this fact.
> 
>> NEW:
>>    Interface Identifiers for stateless address autoconfiguration
>>    are 64 bits long except if the first three bits
>>    of the address are 000, or when the addresses are manually
>>    configured, or by exceptions defined in standards track documents.
>>    The rationale for using 64 bit Interface Identifiers can be found in
>>    [RFC7421].  An example of a standards track exception is [RFC6164]
>>    that standardises 127 bit prefixes on inter-router point-to-point
>>    links. The relationship between prefix length and Interface Identifier
>>    length is discussed in [I-D.farmer-6man-exceptions-64].
>>
>>       Note: In the case of manual configuration, the Prefix and
>>       Interface Identifier can be any length as long as they add up to
>>       128. In all cases, routing and forwarding processes must be
>>       designed to process prefixes of any length up to /128 [BCP198].
> 
> --
> JINMEI, Tatuya
>