ajmas
join:2008-04-14
Canada | reply to eyetack
Re: Question on transition strategy
One thing worth mentioning is in some countries IPv6 is already available. For example, I know Free ( »www.free.fr ), in France already provides this as option. North America seems to be home of the laggards. |
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eyetack
join:2002-09-05
Leicester, MA
 ·BroadVoice
 ·Charter Pipeline
| reply to leware
What I think will ultimately happen is that somewhere along the line, services will get dual-stacked, at least at the edge and DNS will be largely used to start a partial-seamless transition to IPv6.
The bigger problem right now is while most provider-side equipment has been v6 capable, and most modern OSes are v6 capable, almost zero broadband routers are v6 capable. |
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ajmas
join:2008-04-14
Canada
| reply to leware
The excuse I am getting from certain quarters is their upstream provider does not have IPv6 support. So it looks like we need to encourage ISPs, who encourage their upstream providers, and then get the change requests to happen.
Of course in the meantime there are tunnels, such as sixxs.net |
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leware
@tac.net
| reply to bk1e
OK, thanks. From there, it seems TRT is what we would see. There is no "global" strategy for this transition (as I had worngly assumed), and it's up to each IPv6 subnet (at suitable level) to provide these mechanisms. In the ISP case, I presume the ISP would provide that. Getting back to my example, the browser would get AAAA records (assuming I point it to the ISP's DNS-ALG), and the ISP would provide the TRT server to xlate to IPv4. Fine, I'll just wait to see it happen when my ISP offers IPv6 (they have no plans). I guess the IPv6 islands from which I tried things did not offer any of this yet (no wonder then that IPv6 traffic stays so low).
Other ISPs might prefer other approaches, such as Web proxy.
I need to read some RFCs  . |
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ajmas
join:2008-04-14
Canada
| reply to leware
One way could be to use a proxy service. This would provide an IPv6 address for an IPv4 address. Basically you would make a query to the server and it would take care of connecting to the site and sending you back the result. The proxy server would have to be connected to both and IPv4 and an IPv6 network.
Another possibility is that by this time the bell has struck and the news sites are all over themselves announcing the last IPv4 block has been allocated. The result being they are telling everyone that they should be looking to get an IPv6 address and anyone ISP who hasn't already planned to support IPv6 is in panic mode. It is for reasons like this that I feel ISPs should be allowing small number of customers to be beta testing IPv6, so they don't have any surprises when the crunch time comes.
Something else worth checking is if any programs that you use aren't IPv6 ready. If they aren't you should contact the author. |
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bk1e
join:2003-09-15
Austin, TX | reply to leware
The Wikipedia page on IPv6 translation mechanisms lists some technologies that could be deployed to handle this. |
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leware
@tac.net
| I still don't understand how the following transition strategy works in practice. The problem is perhaps not so much technical, but more in the logistics.
Suppose my ISP is an IPv6-only ISP and gives me an IPv6 subnet (/96 presumably, using DHCPv6?). Behind my home router, I run an IPv6-only PC with an IPv6-only browser. I want to access www.ipv4.com, a web server that only has an IPv4 address.
So my browser sends a DNS query for www.ipv4.com. What does it get back? An A record, or an AAAA record. If it's an A record, what does the browser do with it, how does it build an IPv6 address with it? If it's an AAAA record, who (along the DNS path -- the initial DNS server at ipv4.com will return an A record) provides it? I've read of IPv4 addresses being presented in IPv6 with a prefix. But how is this prefix determined. How does the browser know? At first I thought IPv4-mapped addresses were the answer, but I now understand these are merely a local trick for an IPv6-only application to run over a dual stack (but I don't have a dual stack anymore, it's 2013 and we ran out of IPv4 addresses on Dec 21 2012, as the Maya calendar had predicted).
Anyway, let's say we now have a suitable IPv6 address to represent our IPv4 server. The TCP SYN goes out to connect to this server, thru my IPv6-only ISP. Where is the gateway that will map this TCP connection to IPv4? Who owns/runs this gateway? Is that the ISP's job?
I currently have access to IPv6 (via a 6to4 tunnel on my Airport Extreme), but I can't figure out how I would access an IPv4 host from the IPv6 world (granted, it's a bit silly coming from a 6to4 address, as I also have IPv4 obviously, but what if I didn't). What numerical IPv6 address do I use (eg. from some of the IPv6 test tools in the native IPv6 cloud) to ping IPv4 host 4.3.2.1? something:0403:0201 ? What is "something"? Maybe there is no unique answer to that question.
Tia,
Pierre Lewis |
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