Looking for an IPv6 naysayer...

Owen DeLong owen at delong.com
Thu Feb 10 14:58:20 CST 2011

On Feb 10, 2011, at 8:05 AM, Benson Schliesser wrote:

> On Feb 10, 2011, at 9:53 AM, Jack Bates wrote:
>> On 2/10/2011 8:36 AM, Benson Schliesser wrote:
>>> DS-lite is still CGN.
>> It is still LSN, but it is not NAT444, and the failure rate reduces because of that. Also, DS-Lite guarantees that you have IPv6 connectivity. NAT444 makes no such assertion.
> DS-lite *uses* IPv6 connectivity, it doesn't provide it.  That's like saying 6rd or 6to4 "guarantees you have IPv4 connectivity".
> As for NAT444 (or double-NAT):  One could just as easily deploy DS-lite with a NAT444 configuration.  Or deploy CGN without NAT444 (e.g. CGN44, by managing subnets delegated to each subscriber).  The two topics are related but separate.
I think that at the point where you go to NAT444 instead of tunneling the IPv4, it's Dual-Stack, but, not Dual-Stack-Lite.

> In terms of CGN44 versus NAT444, I'd like to see evidence of something that breaks in NAT444 but not CGN44.  People seem to have a gut expectation that this is the case, and I'm open to the possibility.  But testing aimed at demonstrating that breakage hasn't been very scientific, as discussed in the URLs I posted with my previous message.
Technologies which depend on a rendezvous host that can know about both sides of both NATs in a private->public->private
scenario will break in a private->private2->public->private2->private scenario. There are technologies and applications which
depend on this. (I believe, among others, that's how many of the p2p systems work, no?)


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