Subject: RE: The state of IPv6 multihoming development

From: "Michel Py" <[email-masked]>
Date: Sat, 26 Oct 2002 00:18:33 -0700

> No.  The open concern then becomes that of applications
> that carry addresses in the payload -- would border
> routers require a knowledge base of applications to
> translate a la IPv4 NAT?

Yuck. I am totally opposed to ALGs. Although higher layer apps that
embed port numbers or other info in the payload are not elegant, they do
exist. Any solution that requires an ALG is a non-starter.

IPv6 was designed with the implicit promise that we could restore
end-to-end connectivity that was lost with NAT. NAT is not bad; it
simply is a necessary evil. There are no regrets to have invented NAT,
as it was necessary. However, it would be a terrible mistake to
reproduce with IPv6.

Should we go that road, I already have The Perfect IPv6 Multihoming
Solution:

- We already have RFC 1918 for IPv6: Site local.
- We keep the multihomed IPv4 backbone as is, and use 6to4.
- Behind the 6to4 address, we put an IPv6 NAT (TM)(c)
- This solves all the problems in the world: terrorism, hunger, and even
IPv6 multihoming.

You don't like it? Don't invent IPv6 NAT.

Michel.

---

From: Masataka Ohta <[email-masked]>
Date: Sat, 26 Oct 2002 17:12:03 +0859 ()

Michel.

> as it was necessary. However, it would be a terrible mistake to

NAT is unnecessary.

IPv6 people, trying to promoto IPv6 transition, loudly warned IPv4
space exhaustion, perhaps with overestimation.

The result was suppression of IPv4 address allocation, which
promoted people to use NAT.

As a result, IPv4 space won't exhaust very soon that no one really
needs the IPv6 transtion, yet.

Considering that IPv6 still have several flaws, including, but
not limited to that for multihoming, we are lucky thant NAT suppressed
IPv6 deployment.

The remaining problem is that some IPv6 people are opposing to fix
fatal flaws, as the fix will delay the magical IPv6 deployment to
occur within several months, for these seven years.

							Masataka Ohta

---

From: Shane Kerr <[email-masked]>
Date: Sun, 27 Oct 2002 02:13:39 +0100

On 2002-10-26 00:18:33 -0700, Michel Py wrote:
> simply is a necessary evil. There are no regrets to have invented
> NAT, as it was necessary. However, it would be a terrible mistake to
> reproduce with IPv6.

Here's a question:  does the end-to-end principle imply the endpoint
is the application or the network stack on the hosts?

The reason I ask is that I think the mudem idea has merit, even if it
involves a NAT-like transformation from the application point of view.

While eventually building applications that use SCTP might solve the
multihoming needs of many end-users, building a layer that allows all
existing applications to work with a set of addresses can offer enough
benefit now so that the IPv6 folks should hold their noses and
consider the idea.

-- 
Shane Kerr
RIPE NCC