Subject: RE: ocean: do not boil

From: "Hesham Soliman (EAB)" <[email-masked]>
Date: Mon, 23 Sep 2002 23:41:46 +0200

> I mostly agree.
  > 
  > - I think it's not too hard to add magic translating routers (or
  >   whatever) that let IPv4-only boxes at an edge site speak a limited
  >   form of IPv6 as well (been there, done that, at the detail level
  >   it's no worse than IPv4 NAPT and in some ways it's not as bad).
  > 
  > - The exactly parallel case of IPv6-only boxes at an edge 
  > site is not
  >   very hard either, but it's also not very interesting, since
  >   deploying small IPv6-only edge sites onto a dual-service 
  > network is
  >   not likely to be a particularly useful thing to do any time soon.
  > 
  > - The interesting IPv6-only translation case is a big 
  > IPv6-only cloud,
  >   and that one -is- hard, because the translators don't scale well.

=> Agreed. But why would they scale well for a large v4 cloud
if v4 NATs are used?

Hesham

---

From: Rob Austein <[email-masked]>
Date: Mon, 23 Sep 2002 18:07:50 -0400

At Mon, 23 Sep 2002 23:41:46 +0200, Hesham Soliman (EAB) wrote:
> 
> But why would they scale well for a large v4 cloud if v4 NATs are
> used?

Hah, I knew someone would spot that.

Because you don't use 'em for a large v4 cloud.  You use 'em for a
little v4 edge site behind some kind of combination NAPT/NAT-PT box
and use some kind of v6-over-v4 tunneling over the rest of the v4
cloud.  So you've got a lot of little translators converting to IPv6
as early as possible, which scales much better than big honking
translators at the border between the cloud and the rest of the world.

The same approach would "work" for large v6 clouds, but the result
would not be useful, because it'd require so many IPv4 addresses that
there'd be no point to the exercise.

["How do you climb down off an elephant?  You don't.  You climb down
  off a duck, because it's so much safer."]