[arin-ppml] Revised - ARIN-2025-6: ARIN-prop-345: Fix formula in 6.5.2.1c

[William Herrin]

On Wed, Sep 3, 2025 at 12:23 PM ARIN <info at arin.net> wrote:
> https://www.arin.net/participate/policy/drafts/2025_6/
>
> Draft Policy 2ARIN-2025-6: ARIN-prop-345: Fix formula in 6.5.2.1c
>
> Problem Statement:
>
> Sections 6.5.2.1 explains the initial IPv6 ISP/LIR allocation in a way that is difficult to follow and the formula in section (c) does not match the remainder of the text.
>
> Policy Statement:
>
> In 6.5.2.1c, replace:
>
> "This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit X is a multiple of 4 greater than 4/3*serving sites and Y is a multiple of 4 greater than 4/3*end sites served by largest serving site."
>
> with:
>
> "This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit, X is a multiple of 4 greater than 4/3*log_2(serving sites) and Y is a multiple of 4 greater than 4/3*log_2(end sites served by largest serving site).
>
> In 2.15 and 2.16, replace "provider assignment unit" with "provider allocation unit."

Hi folks,

At Friday's AC meeting, I'd like to advance this draft to recommended
status. Section 6.5.2.1 determines the initial ISP _maximum
entitlement_ to IPv6 addresses. ISPs can, of course, request fewer
than this maximum. The draft substitutes the logarithm because the
equation is supposed to provide a CIDR netmask rather than a numerical
count of subnets. It also makes the "provider allocation unit"
language match up throughout the NRPM.

As the shepherd, it is my assessment that this text is impartial and
technically sound. It makes only neutral corrections to existing
policy. As the shepherd, it is also my assessment that it has achieved
general consent within the community as written. I base that
assessment on feedback received both here on the mailing list and at
the October ARIN meeting in Texas (reported here:
https://lists.arin.net/pipermail/arin-ppml/2025-November/038182.html).

I note that a number of respondents also expressed a desire to
simplify section 6.5.2.1 in its entirety, excising complicated math.
Where specifics were suggested, they moved in enough different
directions that as the AC shepherd I recommend further development
happen via a new policy proposal rather than drag this one away from
consensus. Perfect being the enemy of the good.

If you believe the text as written would make bad policy and should
not advance, I ask you to take some time and state your case so that
it can be discussed and debated here in public ahead of the AC
meeting.

Regards,
Bill Herrin