Subject: RE: Will IPv4 be formally deprecated when IPv6 is good enough ?

From: "Michel Py" <[email-masked]>
Date: Tue, 14 Oct 2003 09:48:12 -0700

Mark,

> Mark Smith wrote:
> a) Is IPv4 going to be formally deprecated when IPv6 is good
> enough? If so, are the related IPv4 NAT RFCs also going to be
> deprecated at that time ?

IMHO it's not a matter of being good enough, it's a matter of how many
IPv4 hosts are still up. The IETF deprecating IPv4 would not achieve a
lot; there still are people that use an Apple II and even some that are
writing software and design hardware for it. There will be millions of
diehard IPv4 users for a long while. It's a matter when vendors become
to remove IPv4 from stacks, stop supporting IPv4, and when operators
begin to provide IPv6-only service. In my wildest dreams, 10 years at
least; possibly 20 depending on how good the projections in terms of
IPv4 exhaustion are.

> b) Is IPv6 good enough yet?

Not for most. As long as there is no killer app and as long as IPv4
addresses are available, the investments to move to IPv6 are often not
worth what it brings.

One of the troubles is that v6 does not even do what v4 does: No private
addresses. No PI addresses. No multihoming.

The other trouble is that there is no way to do without IPv4 as of
today. In the enterprise, if someone that implements IPv6 today could
plan on IPv4 removal within two or three years, that would be
considered, but operating dual-stack for 10 or 20 years when IPv4
provides all necessary functions is a waste of money. Keep in mind:
peer-to-peer applications from each desktop to every possible host on
the Internet is not the highest priority of enterprises; it actually is
heavily filtered and firewalled both ingress and egress. As far as the
consumer goes, most on-line gaming and p2p now works across NAT and so
does SIP I hear (with STUN). The only way the consumer is going to
accept IPv6 is when it does not know it's there, which we are not
anywhere close to.

Michel.

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From: Fred Baker <[email-masked]>
Date: Tue, 14 Oct 2003 10:52:10 -0700

At 09:48 AM 10/14/2003, Michel Py wrote:
>In my wildest dreams, 10 years at least; possibly 20 depending on how good 
>the projections in terms of IPv4 exhaustion are.

Frankly, it's not about IPv4 exhaustion, it is about market adoption of IPv6.

IPv4 address exhaustion will never occur. As we approach 100% allocation 
(being now a tad over 60% allocation), the level of administrative pushback 
on a new allocation requests will increase, until they get to a point where 
ISPs will find it simpler and more cost-effective to purchase allocations 
from each other. A market will develop, and the price of an allocation will 
change as demand approaches supply. Eventually, the price of purchasing an 
allocation from another ISP will be perceived and used as a competitive 
weapon, and the market will become a very difficult one. But supply will 
never become zero. It will simply become expensive.

That is economics 101.

We will, at the same time, go through an S curve in IPv6 deployment. We 
currently see a certain level of ISP and Enterprise deployment, and 
sometimes see edge-ISP-edge connectivity, most commonly on research 
networks. At the point where it becomes probable that the only or preferred 
way one can access a peer enterprise with which one has or seeks a business 
relationship is via IPv6, perhaps for some critical application, IPv6 
deployment will start to grow very strongly. As it approaches saturation of 
the current IPv4 Internet, systems which choose IPv6 in preference to IPv4 
will use IPv6 when they can, and IPv4 traffic will start to subside. When 
IPv4 volume becomes too marginal, ISPs will start shutting it down.

The question(s) that raises are "will <pick a point in that game plan> ever 
occur, and if so, when?"

My crystal ball is as cloudy as anyone's. But I would expect that it is all 
a matter of economics.

---

From: Geoff Huston <[email-masked]>
Date: Wed, 15 Oct 2003 05:54:41 +1000

At 10:52 AM 14/10/2003 -0700, Fred Baker wrote:
>>In my wildest dreams, 10 years at least; possibly 20 depending on how 
>>good the projections in terms of IPv4 exhaustion are.
>
>(being now a tad over 60% allocation), the level of administrative 
>pushback on a new allocation requests will increase, until they get to a 
>point where ISPs will find it simpler and more cost-effective to purchase 
>allocations from each other. A market will develop, and the price of an 
>allocation will change as demand approaches supply. Eventually, the price 
>of purchasing an allocation from another ISP will be perceived and used as 
>a competitive weapon, and the market will become a very difficult one. But 
>supply will never become zero. It will simply become expensive.
>
>That is economics 101.

And is also described in RFC 1744.

>My crystal ball is as cloudy as anyone's. But I would expect that it is 
>all a matter of economics.

Indeed. The only other factor here is that it is not entirely a clean 
substitution,
as NATs provide an alternative product which is an imperfect substitution. 
The extent
to which the market, over the past few years, has tended towards NATs despite
the negative effects in both local and network domains  is quickly
becoming the dominant factor in any economic consideration of this entire
IPv4 / IPv6 area.

   Geoff

---

From: "Christian Strauf (JOIN)" <[email-masked]>
Date: Wed, 15 Oct 2003 08:13:44 +0200

> My crystal ball is as cloudy as anyone's. But I would expect that it is all 
I very much agree with you on this point. The problem is that right now
it's too hard to sell IPv6 (in the literal sense of the word). I believe
that one of the reasons for this is that some features that are
theoretically distinctly easier to realise with IPv6, e.g. easier
end-to-end security or de-NAT-ification because of bigger address space,
need a lot of improvement and development to be deployable in a
commercial surrounding. E.g., unless there are (simplified speaking)
stable and good interoperable IPsec implementations for improved
end-to-end security and a good number of firewalls with stateful
filtering to really replace current v4 solutions that employ NAT, it
will be difficult to convince sales people that there actually is
something about IPv6 that can be sold as a feature that makes it better
than IPv4 (if we leave aside IPv4 address exhaustion for the moment).

It would make sense to look into which implementations need to be
programmed first to create a market for IPv6 and to write proposals on
what kind of implementations that might be. However, I believe that this
is not the IETF's task, or is it?

Cheers,
Christian

-- 
JOIN - IP Version 6 in the WiN  Christian Strauf
A DFN project                   Westfälische Wilhelms-Universität Münster
http://www.join.uni-muenster.de Zentrum für Informationsverarbeitung
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From: Iljitsch van Beijnum <[email-masked]>
Date: Wed, 15 Oct 2003 12:23:45 +0200

On 14 okt 2003, at 19:52, Fred Baker wrote:

> IPv4 address exhaustion will never occur.

Yes, it would be interesting to see the justification needed in order 
to be assigned the last remaining IPv4 address.  :-)

And obviously at some point people are going to stop throwing around 
subnets but tunnel individual IPv4 addresses (possibly over IPv6) so 
each and every address can be made useful.

[...]

> The question(s) that raises are "will <pick a point in that game plan> 
> ever occur, and if so, when?"

> My crystal ball is as cloudy as anyone's. But I would expect that it 
> is all a matter of economics.

And we all know economics is just better paid psychology. At some point 
people are going to act on their expectations of what others are going 
to do. Look at the DoD move: they are now requiring v6 because they 
expect the market to pick it up and they don't want to be left behind. 
The market sees the DoD requires it so they start to pick up IPv6 
too...

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From: John Gregson <[email-masked]>
Date: Wed, 15 Oct 2003 14:36:20 +0100 (BST)

Dear Mr Py,

Sorry, could you run that past me one more time ..............?

J