OpenDNS, the largest reverse DNS system on the Internet (the service that connects names to numbers), launched what it calls an “IPv6 sandbox” this week–the first of many announcements that will lead up to World IPv6 Day on June 8.
What is this IPv6 sandbox? I spoke with OpenDNS CEO David Ulevitch to find out. In his words, “It’s a free, publically available DNS server that’s listening on IPv6, where IPv6 is its core competency. It will still do IPv4 DNS addressing, but it provides a way for network administrators to start testing IPv6, to try browsing IPv6 websites and make sure all of that stuff works.”
This gives all of you IPv6 newbies a chance to play with the protocol a full month before world IPv6 Day, so that you can surf the IPv6 Web on June 8th. Not only this, but using the IPv6 sandbox will help your IPv6 training so that you can apply it to your enterprise network.
Ulevitch says OpenDNS is doing this for network engineers who may not be at the cutting edge of technology experimenting with an IPv6 transition: “We want to tell them, ‘look, it’s easy to do this on your desktop even: Get an IPv6 address; you can go to someone like Hurricane Electric and they’ll give you a tunnel to the IPv6 Internet; and then you can go to OpenDNS and point your DNS to an IPv6, publically-available, reverse DNS server, and start browsing IPv6 websites without relying on IPv4 at all.”
Those unfamiliar with how IPv6 works may be wondering, why do I need to use OpenDNS? Can’t my Internet service provider (ISP) connect me to the IPv6 Internet?
According to Ulevitch, even when your ISP gives you an IPv6 address for your computer, the DNS server that you’re talking to is still over IPv4. This means ISPs haven’t done anything to solve the migration of endpoints, desktops or even content and services to IPv6–they’ve just given you a number and solved the problem of you not having an IP address.
“Most people do not use an IPv6-capable DNS server. If you don’t have one of these, you’re not going to be able to reach any resources that are only available using IPv6,” Ulevitch said.
Here’s what he means: When someone gets an IP address from their Internet provider, that often comes along with a DNS server. So when you type in something like www.yahoo.com, your Internet provider’s DNS server translates that into the IP address and takes you to Yahoo.com. Now, even if your Internet provider gives you an IPv6 address, you’re still going to be talking to that same old IPv4 DNS server, so that when you ask for www.yahoo.com, it’s only going to give you the IPv4 answer.
Is this “IPv4 answer” represented by a 404 error? No, because anyone providing IPv6 content hasn’t also shut off IPv4.
“I think that’s something that most people don’t fully understand,” Ulevitch said. “So for everyone who has IPv6, if they’re still talking to an IPv4 DNS server, they’re probably just going to get that website over IPv4 even if they have an IPv6 Internet connection. But if they’re using a DNS server that’s speaking IPv6, then they’ll go to the IPv6 website and they’ll fall back to IPv4 if the website doesn’t have it.”
Why else will OpenDNS be important come IPv6 migration time?
“One of the things that people forget with IPv6 and even DNS is that, DNS was invented so that people didn’t have to remember those IP address numbers. And while some people can remember the IPv4 numbers–with IPv6, it’s a non-starter; it’s 128 bits long, there’s no way people are going to memorize these things. So DNS is really a key piece of IPv6 adoption, so that people can start to serve resources using IPv6. But without DNS it’s not going to happen,” Ulevitch said.
He admitted that there are not a lot of resources that are only available on IPv6 today, but that’s going to change as more people start to adopt IPv6 because IPv4 addresses will have gone. “At some point they’re going to have to give up IPv4 addressing for some resources like peer-to-peer services or websites or whatever it is,” Ulevitch said. Then your only option will be to use IPv6.