There are some transitional technologies that can help to preserve IPv4 addresses, including carrier-grade network address translation, which lets many endpoints share a single IPv4 address, Levy said. However, this type of address translation , according to some experts.

In addition, the special IPv6 Web pages that users were accessing on Wednesday didn't offer any special features or even higher performance than the IPv4 versions, participants in the event said. In fact, engineers were watching to see whether going to an IPv6 site via one of the tunneling protocols would make the experience worse than normal, according to Labovitz.

Yahoo made the HTML components of its Yahoo.com front page available via IPv6 and made the experience the same as for the IPv4 version, said Yahoo IPv6 Evangelist Jason Fesler. The company does not see IPv6 leading to new user experiences in the future, he said. "IPv6 is just a preservation of what we enjoy today," Fesler said.

Though the traffic data from World IPv6 Day didn't reveal how users came to visit IPv6 pages, many probably didn't even know they were doing so, Labovitz said. Some operating systems will automatically try to go to an IPv6 page if it is offered, he said. Part of the purpose of World IPv6 Day was to test whether those systems would get to the sites or run into problems along the way. If all the software, hardware and network components along the way were not designed correctly or were out of date, end users might have experienced problems, he said. Those issues seemed to be rare on Wednesday, according to event participants and researchers.

Because it took place on the Web, the test also led to a day with a more balanced mix of uses for IPv6, which is usually dominated by peer-to-peer file sharing. College students and other users concerned about network management techniques to discourage file sharing have discovered that these tools often don't work with IPv6 traffic, Labovitz said. This aspect of the new protocol is one that should command IT administrators' attention, because it has implications for security, he said.