Lots of Foot Dragging on IPv6

The IPv4 address space is near exhaustion, yet a new report claims that traffic on the modernized IPv6 protocol is slow and migration to the newer address spaces is sluggish.

In a year-long study of 2,393 peering and backbone routers conducted by Arbor Networks, the majority of respondents (customer and peering interfaces) said IPv6 traffic is a small percentage of overall traffic.

What gives?

“What we expected to find is that the migration to IPv6 is slow,” Scott Iekel-Johnson, principal software engineer at Arbor Networks, told InternetNews.com. “I don’t think you’d find anyone that expected there to be a significant ramp up in IPv6 usage. What was surprising in what we found is that there is no migration.”

That’s not to say people aren’t using IPv6 and usage is not growing. Just not by as much as expected, given the size of the problem with Internet address space crowding. Arbor reported that IPv6 traffic grew to a peak of 150 mbps in the summer of 2008 from approximately 50 mbps in the fall of 2007. In comparison to IPv4 traffic though, Arbor reported that for the year that they have been looking at IPv6 traffic it only represented 0.0026 percent (or 26 one-hundredths) of IPv4 traffic.

“We saw a flat proportion of IPv4 to IPv6 over the course of the year,” Iekel-Johnson said. “So although in aggregate IPv6 did grow, it’s growing at about the same level that general Internet traffic is growing.”

Arbor’s study looked only at IPv6 traffic that is tunneled over IPv4, as opposed to looking at native IPv6 traffic. Tunneled traffic allows for dual stack applications where both IPv4 and IPv6 can co-exist on a network. According to Iekel-Johnson, native IPv6 traffic does exist but the reporting infrastructure is not able to measure it in the same way that IPv4 traffic can be measured.

Arbor’s study did not specifically break out geographical disparities in IPv6 usage. In fact, the study represented some 65 ISPs in the Americas while only 6 ISPs from Asia Pacific are included. American carriers own more IPv4 address space than other geographies, which has been seen as a reason why adoption has been faster in Asia.

“We have some monitoring in Asia but we would like to see more there obviously Iekel-Johnson admitted. “It’s not quite as comprehensive as the European and North American measurements.”

Though Arbor’s study may have some issues, at least one major IPv6 vendor praised the study.

“In general, we agree with the findings of the report issued today,” Juniper Networks spokesperson Brendan Hayes told InternetNews.com. “It seems comprehensive and we appreciate the value of these types of studies as they help raise awareness and understanding of critical industry issues.”

In the United States there could well have been reason for more IPv6 traffic as the U.S. government had a June 30th mandate in place for IPv6. The mandate came from the White House’s Office of Management and Budget and required federal agencies to be IPv6-compliant. It did not specify that agencies must actually be running IPv6, only that they have the capability to send and receive IPv6 traffic. The mandate, according to Arbor, has not yet triggered more usage of IPv6 yet either.

“We see press releases from lots of providers across the world talking about IPv6 readiness or infrastructure deployed and I’m sure it’s all true it just doesn’t seem like anyone is using it,” Iekel-Johnson said.

IPv4 has a 32-bit address space, which provides for up to 4.3 billion addresses. In contrast IPv6 has a 128-bit address space, which can provide up to 360,382,386,120,984,643,363,377,707,131,268,210,929 possible addresses. Iekel-Johnson noted that IPv4 address space should be exhausted sometime in the 2010/2011 timeframe. Despite that impeding issue, IPv6 adoption still isn’t picking up steam.

“It’s a slow-moving train and there is no perception that there is an immediate problem so there is nothing motivating the switch,” Iekel-Johnson said.

Plus, the content just isn’t there; many websites are not yet optimized for IPv6. Google, for example, just recently opened up to IPv6, but it’s more the exception than the rule.

Even when all IPv4 addresses are consumed, expected sometime around 2010, there may still be some blocks of addresses that can move around. For example, Iekel-Johnson noted that unused IPv4 address might eventually be traded among providers. That would not address the underlying issues of address exhaustion, but it would be just one solution among many.

“This isn’t oil they won’t find another cache to carry us through another five years,” Iekel-Johnson said. “We are running out and we’re going to have to migrate at some point.”

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