
The IPv6 Mess - tragiclos
http://cr.yp.to/djbdns/ipv6mess.html
======
1053r
The problem will solve itself when the price of an ipv4 address becomes
prohibitive. Either that, or telcos will see ipv4 addresses as a valuable
source of revenue and intentionally drag their feet. And then the internet
will die.

~~~
guelo
Yes, a crisis within the next 2-4 years is going to force the issue. This
crisis will cause a major disruption to the way the internet works and will
affect every industry. The sad thing is it didn't have to come to this, notice
that this article refers to discussions from 2002, if the IPv6 transition had
been managed correctly we would now be completing the transition instead of
barely beginning it.

~~~
rms
Unlikely, I think a crisis in 2-4 years will cause a painless transition to
IPV6.

~~~
loup-vaillant
Or it will cause massive adoption of large scale NAT, which will further
centralize the internet. Because such centralization favour few, huge,
powerful players, we may not see the transition at all.

I just hope the current attitude of Cisco is proving me wrong.

~~~
ghshephard
I just wish Cisco would fully support IPv6. Their regression of the protocol
on their routers, firewalls, leaves something to be desired. But, I guess
regression requires users - chicken/egg thing.

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jsz0
_"It gets worse. The IPv6 designers don't have a transition plan"_

This is either an old article or the author is not up to speed. Good example
why you should date your articles. I met with Cisco a couple months ago and
they detailed their IPV6 strategy to us from the service provider perspective.
In short: They're throwing a bunch of different strategies at the problem to
cover all the bases. It's not an elegant solution. More like brute force with
a focus on preserving total interoperability. This stuff is already in the
wild today on a small scale. It works. Comcast, COX, TWC, etc all have active
deployments and are looking at large scale rollouts over the next year.

[http://www.ict-
partner.net/en/US/prod/collateral/iosswrel/ps...](http://www.ict-
partner.net/en/US/prod/collateral/iosswrel/ps6537/ps6553/white_paper_c11-558744-00.html)

~~~
loup-vaillant
The article is dated, but not outdated. The page you linked to is clear: "IPv4
and IPv6 protocols are not directly compatible, and hence various techniques
are necessary for their coexistence". If IPv6 were compatible with IPv4 in the
first place, the "various techniques" wouldn't be necessary, and transition
would have taken years, not decades.

~~~
Chronos
How would you propose making IPv6 compatible with IPv4? Recall that every IPv4
application in the history of Berkeley Sockets has 32-bit address buffers
hardcoded into the binary.

~~~
loup-vaillant
How this hard-coded size renders backward compatibility difficult?

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st3fan
That posting is from 2003.

~~~
imajes
I really wish djb would date his posts. His rants are good, but hard to
contextualize.

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dedward
Part of the reason we don't just map IPV4 space into IPv6 space, I recall
reading, sensibly, was that it would make routing a mess, and potentially even
get messier.

The idea was to re-issue address space in a more coherent manner to make
things easier to manage at the peering level.... which seems sensible.

It also a mistake to think of the internet you see today as "Designed".... the
protocols were designed, but the particular way we use them, the parts we
didn't use, and the way the internet grew as it did was organic, not pre-
planned. To expect some people to get together and come up for a rock solid
plan to migrate all that to IPv6 is to ask for something completely
unprecedented. The tools need to be there to allow for organic adoption and
growth.... and nobody should be "selling" ipv6 addresses.... there are more
than enough to go around, that was the whole point. IP address space was never
intended to be monetized.

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peterwwillis
I recommend everyone take 15 minutes and look up a guide to configure a 6to4
address on any interface they have with a public IPv4 address. Try with the
anycast address first, and if that doesn't work get a tunnelbroker account. My
opinion is all these problems can get solved over time only when everyone is
first connected to the network. (there are some guides to setting up a gateway
for your 'private' hosts, like this: [http://74.125.93.132/search?q=cache:gX-
Stzp_WdgJ:www.anyweb....](http://74.125.93.132/search?q=cache:gX-
Stzp_WdgJ:www.anyweb.co.nz/tutorial/v6Linux6to4+linux+6to4+gateway&cd=4&hl=en&ct=clnk&gl=us&client=firefox-a))

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3h49ry7zg
I'm quite confused why this is getting attention. It's not hugely difficult to
enable a public IPv6 address on a server alongside the IPv4 address. The
advantage of doing so? If one runs a serious website, there are many more
back-end servers that handle database requests etc. than there are user-facing
webservers, and all of these back-end servers can use IPv6 to talk to each
other and the webservers. If IPv6 addresses are cheaper and easier to get,
then it's a win for the company. They can upgrade each internal client-server
pair to IPv6 in unison since they're a single organization.

~~~
russss
That's a silly argument - any site which uses a non-trivial number of backend
servers will have an internal network using RFC1918 v4 addresses, and there's
no shortage of those (djb covers this).

As someone who runs such a site, I'd only think about upgrading the internal
networks to v6 _long_ after the public internet has gone to v6.

~~~
rm-rf
I've heard that for very large service providers, it is possible to run out of
1918's. IIRC Comcast did a presentation where they figured they needed 100
million IP addresses for a nation wide rollout of their triple play service.
They appear to be highly motivated to use 6, as the alternative - partitioned
1918's would be a nightmare.

I agree, though, that exposing your services to the Internet via both 6 and 4
and leaving the backend internal data center at 4 is probably the way to go
for the next decade or so. Heck - we are still running DecNet on production
servers.

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AndrewDucker
An odd article. He seems to think there ought to be a Grand Plan forcing the
transition.

Servers can have both IPv4 and IPv6 addresses, there's no need for everyone to
just switch over at once.

I strongly suspect that the big providers will start rolling it out over the
next couple of years, and that this will filter down to local users after
that.

My main problem is that very few home routers support IPv6, so they'll need to
be replaced. But this can happen over time, with people on IPv4 being behind
NAT, and thus having less accessibility to soem applications, they can make
their own choices about when to upgrade.

~~~
loup-vaillant
Assume that: (1) universal adoption of X is good, (2) individual adoption of X
takes a few time and effort, and (3) individual adoption of X provide no
benefit whatsoever (such benefit will come when everyone has switched).

I think X will never be adopted before either (1), (2), or (3) becomes false.
That or you actually scheme a "Grand Plan forcing the [adoption]".

I the case of IPv6, the author proposed to solve (2) by embeding the switch in
the normal upgrade process, and (3) by making IPv6 backward compatible with
IPv4. That is not forcing anyone. It just removes a huge amount of friction,
solving the chicken-and-egg problem.

~~~
AndrewDucker
I'm not convinced that (3) is going to be true in the long run. It's when
using IPV4 is a problem that people will switch. And that will come when ISPs
start using NAT on their users.

~~~
rm-rf
Agreed,and many customers will switch without knowing it.

If Comcast swapped my cable modem for a V6 capable modem, and if as a part of
routine upgrades, my Dlink-whatever got swapped with one that has native v6,
I'd be on v6 without knowing it. My Vista, Win7, Mac and Solaris clients would
'just work'. I.e. - when I dropped a /64 onto my home lan - consisting of a
handful of laptops and an OpenSolaris server - my Vista, Win 7 and Mac picked
up the V6 network and started using v6 w/o even a re-boot.

The harder part is making a decision to shut off IPV4. It's at that point that
you have to make a service availability decision.

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ahk
My guess is China and/or India will come up with their own solutions for
transition and the rest of the world will be forced to follow that. It will
probably represent a defining moment in history of the internet, when
leadership passes from the West to the East.

~~~
arethuza
What something like putting an entire country behind a NAT firewall? Not sure
that would represent progress - more likely a Balkanisation of the Net.

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stretchwithme
maybe what we need to do is have servers/networks that validate that whether a
client supports IP6 or not. And if it doesn't, start serving those requests
more slowly than others.

Of course, that means a lot of code changes. but it will definitely create
incentives to get ready for a change

if speed declines for you 10% a month for a year, you'll consider upgrading.
and if outages are scheduled for you that at first last 5 minutes, then 15,
then 30, eventually I expect people will take the actions required to get
ready for a scheduled switch to IP6

its all a bit heavy handed though. its much better if we gave people more
performance for making the switch and somehow passed the real costs of the
delay on to people that insist on delaying.

maybe we should just have a market price for ip4 addresses and you pay that
price unless you upgrade

~~~
loup-vaillant
The problem is giving up performance for the current overwhelming majority of
computers. Slowing down YouTube slowing down for IPv4 computer won't create an
incentive to upgrade those computers. It will be an incentive to leave YouTube
for a faster competitor.

This strategy requires a whole group of players to move _simultaneously_.
We're back to the chicken-and-egg problem.

~~~
stretchwithme
well, could the NETWORK serve requests made by IP6-ready machines more
quickly, if so programmed?

~~~
loup-vaillant
It already does for other criteria, like how much is paid by the content
provider to have the relevant cable "still work flawlessly" (such behaviour
sometimes raises a scandal).

The problem is the network you talk about is a bunch of interconnected
machines and cables, each under the control of some entity, which is often a
profitable company. What you propose would be very difficult if you want to
preserve (the illusion of) net neutrality.

