Despite being given nearly three years to make the change, many government agencies won't be ready on June 30 as mandated. And private businesses in the U.S. have barely given IPv6 any thought at all. That may all change soon, as the IPv6-experienced government agencies show others the way—and as American businesses realize they may pay a price for falling behind the rest of the world on the road to IPv6.

"Having the government push this initiative will put a lot of expertise around IPv6 in the marketplace and help businesses understand how they can take advantage of it, and drive the development of many types of new applications," said Tere Bracco, manager of network systems at Cisco Systems. "This government work will result in strong drivers for the private sector as people better understand what you can do with IPv6, and encourage developers to experiment with it even further."

Why the U.S. has been complacent on IPv6

In other parts of the world, the biggest driver behind IPv6 adoption is not innovation, but rather the scarcity of available IP addresses that can be put into use in locating servers, mobile devices, and many different types of sensors on the Internet. IPv4 supports about 4 billion addresses—a lot when the Internet was created but not so many today. By contrast, Ipv6 supports trillions of addresses.

As the creator and first broad user of the Internet (an outgrowth of a military network meant to survive a nuclear war), the U.S. was allotted roughly 70 percent of all available IP addresses during the Internet's formative years. And it has not come close to using its allocation.

But the rest of the world has already begun to run short on IP addresses from its small pool, and governments and companies overseas have moved much more quickly to go to IPv6 and get the extra addresses it provides, said Kazu Gomi, CTO of NTT America, a subsidiary of Japan's largest telco. Asia-Pacific countries have been particularly fast in adopting IPv6, due to their fast growth (especially in the mobile device arena) and because they had less legacy use of IPv4 to convert, he noted.