"The content side is the easy side of the problem. The harder question is: How soon will you have a massive amount of IPv6 clients who need to get to you?" Malan said. "Think about the Linksys modem in your house. There are oodles of crusty old stuff out there that needs to get upgraded. That problem is hard and expensive."
Experts agree that CIOs need to tread carefully where IPv6 is concerned. For now, they only need to worry about IPv6-enabling their public-facing Web sites and Web services. They don't need to worry about upgrading anything behind the firewall on their private corporate networks.
The drop dead deadline for IPv6
When do a company's public-facing Web sites and services need to be IPv6-enabled in order to prevent them from being unreachable to Internet users with IPv6 addresses? Nobody knows for sure when a significant number of IPv6-only users will emerge, but experts say this upgrade needs to be done within the next 18 months.
John Curran, president of the American Registry for Internet Numbers, which doles out IPv4 and IPv6 addresses to network operators in North America, has said the drop dead deadline for U.S. enterprises to support IPv6 on their Web sites is Jan. 1, 2012.
"It needs to be a priority by the end of the year," Hankins agrees. "That coincides with ARIN running out of IPv4 space by the end of the year or early next year, and it also coincides with LTE deployment. LTE is one of the major drivers for IPv6 because they are expected from the beginning to use native IPv6 support in terms of having users access online processes."
The U.S. federal government has established Sept. 30, 2012 as its deadline for all public-facing government Web sites to support IPv6. Federal agencies have a second deadline of Sept. 30, 2014 to upgrade internal client applications that communicate with public Internet servers to use native IPv6.
Alain Durand, director of software engineering at Juniper, says CIOs have at most 18 months to get their Web content ready for IPv6-only customers. Juniper offers a special purpose Web site for IPv6 users - ipv6.juniper.net — today, and it supported IPv6 on its main Web site, www.juniper.net, for World IPv6 Day using its own routers and carrier-grade NAT gear that it calls translator-in-the-cloud.
"Starting to introduce IPv6 and starting to turn it on now would be a reasonable thing to do," Durand says, pointing out that most broadband providers will support both IPv4 and IPv6 for awhile into the future. "In the beginning, IPv6 may go through some sort of NAT, then IPv6 may go native and IPv4 will go through some sort of NAT. The question for CIOs is: When can they offer a better service to their users by offering content natively over IPv6?...There comes a point at which offering content over IPv6 offers a better user experience to customers and offers you as a network manager more flexibility."
Durand says he doesn't know when CIOs will experience traffic management issues on their networks that will encourage them to switch from NAT devices to native IPv6. One worry is that it will be harder for network operators to filter out denial-of-service (DoS) attacks when NAT devices are used to share IPv4 addresses among multiple subscribers. That's the kind of network management issue that will likely prompt network operators to deploy native IPv6 service.
"If you're using IPv6 natively or translator-in-the-cloud, you have access to the originating IP source and you can filter out the DoS attack on this IPv6 address and only remove the bad guy without impacting the other 99 or 999 users," Durand says.
The cheapest, easiest route to IPv6
Experts say CIOs only need to upgrade their public-facing Web sites and services to support IPv6 in the near-term. How long that will take and how much it will cost depends on the size and complexity of a company's Web presence.
Major content providers like Google and Yahoo are upgrading their entire Web server infrastructures to support IPv6, including Web servers, database servers, storage, caching and all the software that's used on these systems. Yahoo has been working on IPv6-enabling its infrastructure since 2008 and has said this is the second-largest engineering effort for its IT department, behind ongoing tech refresh efforts.
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