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

[Fernando Gont <[e-mail]>]

On 06/09/2017 05:31 PM, David Farmer wrote:
> 
> 
> On Fri, Jun 9, 2017 at 1:36 AM, Lorenzo Colitti <[e-mail]
> <mailto:[e-mail]>> wrote:
> 
>     On Fri, Jun 9, 2017 at 1:24 PM, Fernando Gont <[e-mail]
>     <mailto:[e-mail]>> wrote:
> 
>         > However, I think IPv6 implementations that don't support manual
>         > configuration must be able to reject non-64 bit IIDs, since that is the
>         > standard. Saying "SHOULD be 64 bits long" means they "MAY be /81, /99 or
>         > /123", and those are against BCP 204 (RFC 7934).
> 
>         BCP204 talks about multiple addresses. As long as whatever prefix is
>         employed allows for multiple addresses, I don't see how that goes
>         against BCP204.
> 
> 
>     That's not true at all. As an example: see if you can build a
>     network that uses a /99 and satisfies the recommendations in section
>     8 or BCP 204.
> 
> 
> Yes, to meet the specific RECOMMENDATIONS in BCP204 /64 is necessary.

I don't see anything in BCP204 where /64 is a MUST or even RECOMMENDED.


> It seems to me that extremely long prefixes like /120 or longer are
> likely unable to achieve the intent of BCP204 for any significant number
> of hosts. However, anything in the range /112 or shorter should have
> plenty of address to achieve the intent of BCP204 for a quite reasonable
> numbers of hosts, at least many hundreds of hosts.
> 
> So, of the examples you provided, /123 is unlikely to achieve the intent
> of BCP204, but /81 or /99, while they don't meet the specific
> RECOMMENDATIONS of BCP204 there doesn't seem to be any reason they
> couldn't achieve the fundamental intent of BCP204, granted with without
> much sparseness or entropy in the assignments, but that's not
> specifically part of BCP204.

Could you copy&paste the "specific recommendations" you're referring to?

I haven't found any. And I see no reason for which the authors of bcp204
should have cared about a specific prefix length.

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [e-mail]
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