Martin Levy, director of IPv6 strategy at Hurricane Electric, a Fremont, Calif., ISP that claims to have the world's most interconnected IPv6 backbone, says he is struggling with how the Arbor Networks data can be true given the network industry momentum behind IPv6. "Where Arbor measures is not where the predominant IPv6 usage is," Levy says.
BACKGROUND: The 6 biggest misconceptions about IPv6
What's preventing the Internet engineering community from coming up with more complete IPv6 traffic statistics is the fact that few ISPs or their hardware suppliers have deployed a network management tool called NetFlow 9. This industry standard export protocol sends data about traffic flows through the router to an external collection host so that the flow information can be analyzed. NetFlow 9 can be used to separate out and measure IPv6 and IPv4 traffic flows.
NTT America, a leading provider of IPv6 transit services, concedes that it doesn't measure the IPv6 traffic it is carrying separate from overall Internet traffic, so it doesn't know the rate at which its IPv6 traffic is growing.
"Most routers don't have support for counting IPv6 traffic separate from IPv4 traffic on their physical interface counters," explains Dorian Kim, vice president of IP engineering, Global IP Network at NTT America. "By and large, bits are bits to interfaces, and there's been no particular driver for us to track IPv4 and IPv6 separately, especially when measuring IPv6 in the network requires one to instrument NetFlow 9 collection of traffic from the routers."
Kim says NetFlow 9 is "the most likely way we'll be able to account for IPv6 traffic separately from IPv4 traffic. ...We are working with our equipment vendors to have NetFlow 9 export capabilities across all of our network, but that is something that'll happen over time."
NTT America isn't the only ISP that hasn't been able to deploy NetFlow 9. "I heard from a significant cable operator that they don't run NetFlow 9 and hence can't measure IPv6 flows," Levy says.
One reason most carriers don't have NetFlow 9 gathering statistics across their peering and edge routers is because it can cost millions of dollars to deploy.