The 24-hour experiment was , which offers far more potential addresses than the current version, IPv4. More than a thousand Web pages, including ones at Google, Facebook, Yahoo and other major destinations, temporarily were made available over both IPv6 and IPv4. The event was designed to test how well client, server and network components performed when making connections over IPv6.

In fact, the day was less a test of IPv6 and more of the technologies to be used on the way to the day when IPv4 goes away. But those transitional tools are important to try out, because they are likely to come into play for many users and enterprises in the coming years.

For a user to reach a website over IPv6, there has to be an IPv6 address provided for the site and the client system has to be able to recognize and go to that address. Major participants and the Internet Society, which organized World IPv6 Day, reported that few problems arose as users went to the IPv6 versions of pages.

However, most of the additional traffic on Wednesday didn't use IPv6, but rather a variety of protocols designed to allow IPv6 to coexist with networks dominated by IPv4. In most cases the transitional protocols don't help to solve the problem of quickly dwindling IPv4 addresses, according to IPv6 consultant Craig Labovitz, the former chief scientist at Arbor Networks. While this result did not surprise researchers, it signaled that the journey toward IPv6 is just beginning.

Even during the event, IPv6 and related protocols made up only a small portion of the traffic on the Internet. Before the event began at midnight UTC on Wednesday, that share was only 0.135 percent, according to tests by Sandvine, a network equipment maker. During the test, the proportion grew to 0.15 percent, Sandvine said. Others who compiled numbers found different results, because they were measuring different portions of the Internet.