Re: Updated IID length text

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

On 20/01/2017 17:38, Lorenzo Colitti wrote:
> On Fri, Jan 20, 2017 at 4:41 AM, Brian E Carpenter <
> [e-mail]> wrote:
> 
>> However, correct use of Stateless Address Autoconfiguration
>>    (SLAAC)[RFC4862] requires all interfaces on a link to use the same
>> length
>>    of Interface ID. Furthermore, to guarantee robust interoperability of
>> SLAAC,
>>    a consistent length of Interface ID is desirable. For this reason,
> 
> 
> I object to the text "for this reason", because SLAAC is not the only
> reason. There are many reasons, many of which are written in 7421, and two
> sentences in this paragraph are not sufficient to describe them. I propose
> the following alternative, which I believe to be normatively identical:
> 
>    IPv6 routing is based on prefixes of any valid length up to 128 [BCP198].
>    For example, [RFC6164] standardises 127 bit prefixes on point-to-point
>    links. However, the Interface ID of all currently allocated unicast addresses,
>    except those that start with the binary value 000, is required to be 64 bits
>    long. The rationale for the 64 bit boundary in IPv6 addresses can be found in
>    [RFC7421].

Yes, I'll buy 'however'.

   Brian