Yahoo.com yesterday was reachable only with IPv4. But when the company made its IPv6 servers discoverable over IPv6, they started delivering data. This image shows the IP addresses of servers used to supply information for the Web page; green means IPv6 and red means IPv4.
Starting at midnight GMT, many sites started showing their IPv6 servers as being available. Here, pale yellow-green means the site will tell a visitor that an IPv6 server is available for visitors from all the points on the Internet from which the RIPE Internet registry is measuring. Darker colors show lower levels. Many sites already advertised their IPv6 servers, and some still don't, but a few toward the top, including Yahoo, Google, Bing, Facebook, YouTube, and Cisco, show a transition to IPv6 availability.
Shown in green, the percentage of Alexa top-50 Web sites (across multiple top-level domains, not just .com) available over IPv6 spiked during an IPv6 test in 2011 but then leveled out at about 2 percent. It started rising again before the World IPv6 Launch on June 6.
The tests by RIPE, Europe's regional Internet registry, show that the "ping" test of how long it takes to reach an Internet site is faster for IPv6 than for IPv4 -- if you're in North America trying to reach Google.
Arbor Networks, which runs a network with dozens of Internet service providers supplying anonymous data, said it saw a 20 percent increase in the amount of native IPv6 traffic last night after the World IPv6 Launch began.
Erik Kline, one of Google's three engineers dedicated to updating the company's products and technology for IPv6, posted this photo of vegan IPv6 brownies on Google+ today. "Needless to say, I 'allocated some IPv6 space' last night," he joked.