Curran says it's more important for U.S. CIOs to IPv6-enable their Web sites than it is for them to support IPv6 on their internal networks.

"The most important thing for enterprises is to make sure the content on the Internet gets IPv6 connectivity turned on in addition to IPv4. That's the top priority," Curran says. "Changing your internal network to support IPv6 is really based on when you see the benefits of making that transition, and that will vary by company. But your external, public-facing Web site affects many other organizations."

Only a handful of popular U.S. Web sites support IPv6, including those operated by , Netflix, Limelight and .

Usage of IPv6 in 2009, although it still represents a sliver of overall Internet traffic. Several carriers including Hurricane Electric and NTT America reported that IPv6 traffic on their networks doubled in 2009.