[arin-ppml] Draft Policy ARIN-2024-8: Restrict the Largest Initial IPv6 Allocation to /20

[William Herrin]

On Thu, Jun 27, 2024 at 11:27 AM John Santos <john at egh.com> wrote:
> I don't know the use case, and I don't
> think anyone else here does or if they do, they haven't described it.

I don't know the use case that was documented for the /16 allocation,
but I know of a straightforward use case which I believe fully
compliant with ARIN policy, justifies an IPv6 /16 and is utterly
divorced from anything resembling efficient use.

My use case is simple: I want to assign the IETF recommended /48
prefixes to my customers, I want to use 6rd to reach them and I don't
want to map the IPv4 address space directly in to 6rd without
narrowing it to my various IPv4 allocations.

Presto. I need 32 bits to map the v4 address space into 6rd and I want
each to lead to a /48, so I need /48-32 = a /16.

Indeed, I could even justify a /12 if ARIN allowed it since I don't
want my native IPv6 use to overlap 6rd.

I cannot stress enough how wasteful this plan is, but it is
technically compliant with justifiable use under current IPv6 policy.

Regards,
Bill Herrin



-- 
William Herrin
bill at herrin.us
https://bill.herrin.us/