[arin-ppml] Opposed to 2010-9 and 2010-12

[Owen DeLong]

On Oct 14, 2010, at 2:36 PM, Mark Townsley wrote:

> On 10/14/10 11:06 PM, Owen DeLong wrote:
>> 
>> 
>> On Oct 14, 2010, at 1:51 PM, Lorenzo Colitti wrote:
>> 
>>> On Thu, Oct 14, 2010 at 8:02 AM, Owen DeLong <owen at delong.com> wrote:
>>> If you can get 6rd to fit in  single /16, then, perhaps we could consider allowing it to be permanent.
>>> 
>>> However, if ~3,000 ARIN members deploy 6rd /24s, then, you're talking about the vast majority of an entire /12 just in the ARIN region.
>>> 
>>> Why not we make it a /28, and thus give the customer a /60? The customer still gets 16 subnets for his house, and when 6rd goes away (since, as you point out there are other disadvantages beyond address space use compared to               native IPv6), then the subnet will be /56 (since, following your reasoning, that is what competitors with native IPv6 access will be providing).
>>> 
>> /60s are horrible... They completely stifle any ability for the customer to do PD-based topology
>> within the site.
> I think you are assuming what the PD-based topology mechanisms are going to be. They haven't really been designed, and certainly haven't been coded and shipped yet. All we are doing at this point is providing a playing field. Within that field:
> 
> /60 is an *enormous* improvement over /64. Night and day.
> 
> /56 is certainly better than /60, but not night and day as with /64 and /60. 
> 
> The point here is that if we design home routing and PD for 2^4 subnets, it's not hard to take that and extend it for 2^8 or 2^16. Not so if you are starting with 2^1.
> 
With all due respect, I must strongly disagree here. Whatever we decide here will likely impact and set the standards by which home gateways are designed going forward.

We agree that /64 is a non-starter.

I strongly believe that the target should be /48. That 6rd has such terrible deficiencies in its use of address space that we cannot afford /48 and therefore must compromise to /56.

Further compromising to /60 runs the risk of that becoming a de facto industry standard which will potentially be very difficult to overcome.

You asked me to tell you if you are contradicting someone from your organization... You are contradicting Tony
Hain here, or, at least my understanding of what Tony has been saying.

> Consumer products will be designed to operate within the lowest common denominator of the above. If we can make that /60 vs. /64, that's a big win and we might see some potential for upsell into /56 for "bigger home networks". But, if we have to do a ton of work to make networks work within a single /64 anyway, once we have done that, it's hard to argue for supporting multiple subnets as well. I'm trying to avoid having to do the work at all for /64, but that can only happen if I know the minimum number of subnets in the home is greater than 1. 
> 
That is, indeed, the source of my concern. If consumer products are developed only to the lowest common denominator,
we risk establishing /60 as that point. /56 is bad enough. As I have said, we should strongly encourage /48 as the
standard around which development occurs while recognizing /56 as a necessary limitation of 6rd.

I don't think we are disagreeing here, and I don't think anyone is advocating /64s. The AC has approved and forwarded
to last call policy which enables /56s for 6rd, but, encourages treating those as temporary and transitional in nature.
I think this is the best compromise.

Owen

> - Mark
> 
>> 
>>> I would point out that the only ISP I am aware of that is conducting residential trials of IPv6 seems to be talking about giving only a /64 to the home by default due to CPE issues. To me, that is a much greater problem than having a /60 instead of a /56, because with a /64 you can't do any subnetting at all.
>> 
>> True... /64 should be even more discouraged than /60, but, the reality is that we should look at
>> /56 as a temporary expedient due to inefficiencies in 6rd and consider /48 the norm.
>> 
>> Owen
>> 
> 

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