Subject: When will ISP's switch over to IPv6 and how will it affect customers?

From: "Hex Star" <[email-masked]>
Date: Sun, 26 Aug 2007 16:48:10 -0700

There's a lot of discussion on these lists about switching to IPv6 and what
technical changes/implementations will be necessary for ISP's when the move
is made but when will the move be made? Will the move be gradual so that
users who have a IPv4 modem will have time to exchange the modem for a IPv6
compatible one? What will happen to websites on networks that haven't yet
moved over to IPv6?
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From: Keith Moore <[email-masked]>
Date: Sun, 26 Aug 2007 20:11:29 -0400

IPv6 and IPv4 can be expected to coexist for a long time.  Individual
ISPs can start supporting IPv6 whenever they believe that it is in their
interests to do so; some are doing so already.

IPv4 and IPv6 can be run over the same media, at the same time.  So IPv6
does not, in general, require a new modem.  In some cases where the ISP
supplies a box to the customer that does more than just transmit IP
packets to and from the customer's network (for example, boxes that act
as DHCP servers), an upgrade to that box will be advantageous.   However
there are standard ways of transmitting IPv6 packets over IPv4 so even
legacy routing equipment can be used to connect to IPv6.

Most computers and web browsers these days can support IPv4 and IPv6 at
the same time.  If a web site supports IPv6, the site's IPv6 address
will be used, but if the site still supports only IPv4, the IPv4 address
will be used.  This is a bit simplified but it is basically how things
work.  In addition to web browsers, most other applications in use today
can tolerate a mixture of IPv4 and IPv6 nodes.

> There's a lot of discussion on these lists about switching to IPv6 and
> what technical changes/implementations will be necessary for ISP's
> when the move is made but when will the move be made? Will the move be
> gradual so that users who have a IPv4 modem will have time to exchange
> the modem for a IPv6 compatible one? What will happen to websites on
> networks that haven't yet moved over to IPv6?

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From: Iljitsch van Beijnum <[email-masked]>
Date: Mon, 27 Aug 2007 17:17:57 +0200

On 27-aug-2007, at 1:48, Hex Star wrote:

> There's a lot of discussion on these lists about switching to IPv6  
> and what technical changes/implementations will be necessary for  
> ISP's when the move is made but when will the move be made? Will  
> the move be gradual so that users who have a IPv4 modem will have  
> time to exchange the modem for a IPv6 compatible one? What will  
> happen to websites on networks that haven't yet moved over to IPv6?

In order for a session to be IPv6, all of the following must support  
IPv6:

1. Web browser/client application
2. OS
3. Home gateway
4. Last mile
5. ISP backbone
6. Content network backbone
7. Firewalls/load balancers
8. OS
9. Server application

OSes, a lot of applications/servers (not all, though) and backbone  
routers can all do IPv6 without too much trouble. So that leaves:

3. Home gateway

Although there are a few that will do IPv6, the popular ones don't  
and there is currently no easy way to make IPv6 happen between a home  
gateway and an ISP connection.

4. Last mile

The basic technology to get IPv6 packets across different types of  
last mile networks exists, but I'm not sure to which degree the large  
access concentrators support it. And, as mentioned under 3., there is  
no clear way to provision IPv6 addresses to customers.

7. Firewalls/load balancers

Firewalls, getting there, but ultraconservative by their nature. (A  
lot of them still have trouble with RFC 1323 after 15 years.) I have  
no idea about the status of load balancers, but they need work, I  
gather.

IPv6 support was supposed to happen in 3G wireless. I don't think it  
did, at least not across the board. IPv6 support was supposed to  
happen in ADSL2 modems. Again, don't think this happened. It's now  
supposed to happen in DOCSIS 3 (cable modems).

In my opinion, until the IETF or an industry group comes up with  
something that tells vendors on different sides of the local loop how  
they're supposed to talk to each other to make IPv6 happen  
automatically, not much is going to happen unless demand reaches  
"riot in the street" levels. Note that all the necessary ingredients,  
in the form of numerous protocols, are available, it's just not clear  
which one you should use for what in which way. (This always happens  
when there is a new technology: in the early days of dial-up, you  
needed AT commands and login scripts and in the early days of ISDN  
you had three or four different protocols, but after a few years, the  
industry settled on a default choice that worked without user  
intervention.)

However, there seems to be lack of a big picture view in the IETF.  
For instance, you can get everything you need from PPP with IPv4, but  
you currently need to run PPP with stateless autoconfiguration for  
your address and DHCPv6 for nameserver addresses. But many vendors  
disable the former for IPv6 and don't implement the latter. So in  
practice, you can't do IPv6 over dial-up.

I expect the fact that IPv4 address space is running out within 5  
years or so will be enough to push people to make progress in this  
area and others, and the need to test IPv6 in various scenarios will  
make sure that the protocol will be made available in more and more  
places, but probably not yet at production quality.

Once the big IPv4 address crunch starts NAT deployment will go  
through the roof and more and more people will either offer IPv6 or  
ask for IPv6 to get around NAT. If by that time, $50 home gateways  
can do IPv6, I expect ISPs, especially address starved ones, to  
enable IPv6 and users will be using it without a conscious choice on  
their part. At this point, it becomes interesting for the content  
networks to make sure they're reachable over IPv6 too, especially  
ones that need something better than garden variety client/server  
TCP, i.e., video streaming. Same thing for peer-to-peer applications.

Modems that don't do IP but only ethernet don't have to be replaced  
or upgraded, but anything that touches IP does.

People will continue to reach most of the internet over IPv4.  
Initially through NAT, later maybe by ditching IPv4 locally and using  
a proxy or translator device a bit futher upstream.