OpenDNS CEO David Ulevitch says he is launching the IPv6 service now to help website operators and networking firms prepare for World IPv6 Day, a 24-hour test of IPv6 that is scheduled for 8 June. Sponsored by the Internet Society, World IPv6 Day has attracted more than 160 participants, including some of the Internet's leading content providers, such as Google, Yahoo and Facebook.
"World IPv6 Day ... is all about getting organisations to make their resources available over IPv6," Ulevitch says. "It's a flag day. It's a point that you can use to convince your boss that IPv6 is worthwhile. ... It's not really for the end users; it's really for the network administrators, the IT guys, to figure out that it's not that hard to do IPv6."
OpenDNS says it will participate in World IPv6 Day by having all of its websites support IPv6 by default on 8 June.
OpenDNS said it was the first to offer a free DNS recursive service that supports IPv6. Recursive DNS services allow Internet users to find websites by typing in their domain names and pulling up the corresponding IP numbers. In contrast, authoritative DNS services allow website operators to publish their domain names and corresponding IP addresses to Internet users.
"We are not aware of anybody else doing" a free recursive DNS service that supports IPv6, Ulevitch says. "There's no financial angle; we just want to encourage people to use an IPv6 DNS service."
Until now, network engineers experimenting with IPv6 had to encapsulate their traffic to transverse IPv4-based DNS servers.
"People want to experiment with IPv6 and we have DNS set up to support them," Ulevitch says. "We are trying to help push traffic and resources over to IPv6. If you actually want to reach IPv6-only resources, you need to use DNS resources that you can talk to over IPv6."
The IPv6 addresses for the OpenDNS IPv6 DNS Sandbox are: 2620:0:ccc::2 and 2620:0:ccd::2.
Internet companies like OpenDNS are promoting IPv6 because the Internet is running out of IPv4 addresses.
IPv4 uses 32-bit addresses and can support 4.3 billion devices connected directly to the Internet. Most IPv4 addresses have been handed out. The free pool of unassigned IPv4 addresses was depleted in February, and the Asia Pacific regional Internet registry said in April that it has doled out all but its last 16.7 million IPv4 addresses which are being held in reserve for startup network operators.
IPv6, on the other hand, uses 128-bit addresses and supports a virtually unlimited number of devices - two to the 128th power. But despite its promise of an endless supply of address space, IPv6 represents only a tiny fraction - less than 0.03 percent - of Internet traffic.
Ulevitch said the new OpenDNS IPv6 service would allow Internet users to access IPv6-only websites, which he admits are a "very,very small'' portion of Internet resources.
OpenDNS says it has more than 20 million users globally, representing one percent of all Internet users. The company's free service is popular with US public school systems, while its paid enterprise version has attracted corporations of all sizes.