Re: [v6ops] reclassify 464XLAT as standard instead of info

[Lorenzo Colitti <[e-mail]>]

On Sat, Sep 23, 2017 at 6:25 AM, Mark Andrews <[e-mail]> wrote:

> Stop exaggerating.  Google went and added CLAT to the Android.  They
> can just as easily add DS-Lite to Android and we would have billions
> of machines that support DS-Lite.  Just because NAT64 and 464XLAT are
> sexy doesn't mean that it is good technology.
>

We added 464xlat to Android because there were credible deployment plans in
place for 464xlat on real networks that Android devices connect to. In
hindsight, we were right, as 464xlat went from credible plan to successful
deployment with an installed base in the tens of millions.

I personally think that if we had not done this, we wouldn't have IPv6-only
mobile networks today and we'd all still be lamenting the chicken and egg
problem for IPv6-only networks. Getting rid of IPv4 in the network is a
great step forward, and as Apple has shown, once that's happened, host OSes
can start removing IPv4 access from applications, too. (And make no
mistake: without 464xlat, those networks would *not* have gone IPv6-only,
and it would have been much harder, or even impossible, for Apple to say
that apps must operate in IPv6-only environments, because there would have
been no such environments.)

DS-Lite has no such credible deployment plans in place. Wifi networks are
going to provide IPv4 for many years. Mobile networks were never going to
deploy DS-Lite because the encapsulation would have broken their billing
platforms. And so, here we are.

We'll all get to IPv6-only eventually, and some time after that, we'll get
rid of IPv4. At that time, you can salt the earth over 464xlat if you want.
But until then, I wouldn't be too eager to bash 464xlat as a technology. It
was the right thing to do at the time.