Re: [**EXTERNAL**] Re: the race to the bottom problem

[Gyan Mishra <[e-mail]>]

On Fri, Nov 6, 2020 at 3:09 PM Brian E Carpenter <
[e-mail]> wrote:

> On 07-Nov-20 03:30, Mudric, Dusan wrote:
> > Would it help if the problem statemen clarifies that:
> >
> > - There is no race to the bottom. We are not trying to solve ISP problem
> by allowing longer than 64bit prefixes,
>
> Unfortunately, once you push code allowing >64 subnet prefixes for SLAAC
> into the wild, you do automatically give ISPs a path to to allocating
> longer prefixes to customers, and all history tells us that some of them
> will follow that path.
>
> Once that code is out there, the race to the bottom is enabled.
>
> Even draft-bourbaki-6man-classless-ipv6 doesn't recommend changing the /64
> default for SLAAC. (If it did, my name would not be on that draft.


   Gyan> I am not sure I understand the comment of pushing >64 subnet
prefixes out into the wild as if by doing so we are breaking IPv6.  Also
can you enlighten me on the history of another instance where a similar
apples for apples comparison where something similar was done by ISPs?

So once the code is there it is only in theory that the race to the bottom
will be used by providers once enabled.  We have a BCOP RIPE-690 which
would still apply to broadband carriers recommendation of /56 or larger and
with 3GPP mobile handset a /64.

If we have expect that operators to not follow BCOP why have a BCOP.

Could we not have an IPv6 allocation guideline for mobile operators to
support a minimum allocation of /64 similar to RFC 3177 or RFC 6177.  What
good is an IETF protocol specification if it is not followed by operators.

Bourbaki draft states that free BSD ships with SLAAC of any length.  That
is a good point duly noted by the draft.

So in theory if router manufacturers decided they could ship code now that
supports any prefix length and Free BSD and their maybe other OSs out there
that may work.

Bourbaki draft is actually referenced in both of our drafts and Bourbaki
draft clearly recommends any IID length.

Introduction:

   Over the history of IPv6, various classful address models have been

   proposed, none of which has withstood the test of time.  The last
   remnant of IPv6 classful addressing is a rigid network interface
   identifier boundary at /64.  This document removes the fixed position
   of that boundary for interface addressing.


5 <https://tools.ietf.org/html/draft-bourbaki-6man-classless-ipv6-05#section-5>.
Recommendations


Note that OpenBSD ships with SLAAC for lengths longer than /64.


   Nonetheless, there is no reason in theory why an IPv6 node should not
   operate with different interface identifier lengths on different
   physical interfaces.  Thus, a correct implementation of SLAAC must in
   fact allow for any prefix length, with the value being a parameter
   per interface.  For instance, the Interface Identifier length in the
   recommended (see [RFC8064 <https://tools.ietf.org/html/rfc8064>])
algorithm for selecting stable interface
   identifiers [RFC7217 <https://tools.ietf.org/html/rfc7217>] is a
parameter, rather than a hard-coded value.





>
>    Brian
>
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*Gyan Mishra*

*Network Solutions A**rchitect *



*M 301 502-134713101 Columbia Pike *Silver Spring, MD