Re: [v6ops] I-D Action: draft-ietf-v6ops-unique-ipv6-prefix-per-host-07.txt

[Alexandre Petrescu <[e-mail]>]

Le 21/08/2017 à 20:08, 神明達哉 a écrit :
> At Fri, 18 Aug 2017 21:46:18 +0200,
> Alexandre Petrescu <[e-mail]> wrote:
> 
>> Here, still it makes sense to allow for prefixes shorter than 64 (i.e.
>> unique /63 prefix per Host, such that it can further grow the network by
>> becoming a Router).
>>
>> The draft says:
>>> a Unique IPv6 prefix (currently a /64 prefix) and some flags.
>>
>> That "currently a /64" sounds as a hardcoded value.
>>
>> It should be something like: "a variable length whose value could be /56
>> for example; it could also be /64".
> 
> Today you can't use a prefix for SLAAC unless its length is 64 due to
> the facts that
> - All today's defined IIDs have 64 bits in length
> - Hosts reject the prefix unless the sum of the prefix's length and
>    the IID length equals to 128 (which means the prefix length must be
>    64) according to RFC4862
> 
> You may not like it or might want to say "it doesn't have to be that
> way"), but that's the fact today.  As long as
> draft-ietf-v6ops-unique-ipv6-prefix-per-host talks about today's
> practice, I don't think anything that doesn't work today is in the
> scope of this document.
> 
> We may or may not choose to include the specific number of 64 in the
> doc, on which I don't have a strong opinion.  But ""a variable length
> whose value could be /56 for example" is very misleading since /56 for
> SLAAC doesn't work today (perhaps "could" tries to express the subtle
> nuance, but that would be quite misleading).

Because I agree with you, I will reformulate:

Leaving 64 there comforts operators and equipment manufacturers in ==64 
barriers preventing the network to grow at the edges.

HTTP parallel:  it would be unconceivable to write an I-D with 
'currently' HTTP traffic is in clear, requesting the WG to make it a 
BCP.  Rather suggest HTTPS be BCP.

IPv4 parallel: write an "IPv4-prefix-per-Host" I-D, because 'currently'.

Alex

> 
> --
> JINMEI, Tatuya
>