[arin-ppml] Draft Policy 2011-5: Shared Transition Space for IPv4 Address Extension - IAB comment

[Owen DeLong]

On Jun 29, 2011, at 6:09 AM, Joe Maimon wrote:

> 
> 
> Owen DeLong wrote:
>> 
> 
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>> Due to the support issues, no provider in their right mind is going to use 1918 space for the middle-layer in a NAT444 scenario.
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> Due to the support issue, no provider in their right mind is going to share addresses across multiple customers.
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> Apparently, when it comes to support issue, the question remains one of degree. And I disagree sharply with you as to the effect on the equation the use of 1918 brings.
> 

You can disagree all you want, but, the majority of (large) providers that have studied the issue do not.

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>> As such, the question remains the same...
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>> Do we allocate a single /10 so that everyone can use the same address space, or, do we force each provider to build their own collection of GUA addresses allocated to this same purpose?
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>> Owen
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> False dichotomy.
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> Or providers will use GUA regardless of the /10. Or providers will pool a collection together. Or providers will go ahead and use space that already exists, either their own or rfc1918 or even 240/4.
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Lack of support in the CPE makes 240/4 a likely non-starter for this.

RFC-1918 is also a non-starter for most of the large providers. They'll get GUA allocations before they'll use 1918 in most cases.

I doubt anyone wants to use GUA regardless of the /10, what would be the advantage?

As to pooling a collection together, that's essentially the same effect as allocating this /10, just in a much more complicated and less documented/reliable manner.

So, basically you've narrowed it down to two variants of the /10 and GUA as the other two options you presented are unlikely to see much acceptance vs. the available alternatives.

Of the remaining feasible alternatives, 2011-5 is certainly the cleanest approach. I hope the IAB/IETF will reconsider this and bring it to a favorable outcome.

> Even if they do not find those options as attractive as this /10.
> 

If I were to rank the options in order of attractiveness (from an ISP perspective), they would be:

	2011-5
	Consortium-based assignment
	Community pool of GUA addresses
	New GUA allocations or assignments from RIR (individually to various ISPs)
	Use of existing GUA space (forcing some fraction of existing customers into NAT-444 degraded services)
	Use of RFC-1918 space
	Use of 240/4

I'm pretty sure that they'll find a way to make one of the top 4 work. Since the first 3 basically boil down to the same effect as 2011-5, I would say that it's a relatively safe bet that the dichotomy between 1-3 and 4 is a valid and accurate one.

Owen