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

[Owen DeLong]

> On Jun 27, 2024, at 11:49, William Herrin <bill at herrin.us> wrote:
> 
> 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.

I’m pretty sure that ARIN has repeatedly rejected various versions of this use case already and would do so again.

> 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.

It may be a “use case”, but not one that I believe ARIN would consider to be in line with policy as currently written.

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

Pretty sure that’s not actually the case.

Owen