A recent study has revealed just how slow the rate is for of adoption for IPv6, the next version of the internet's main communications protocol. The lack of enthusiasm for the new protocol has some experts saying black markets where companies trade unused IP addresses may be only a few years away.
The report, from Arbor Networks, claims to be the most comprehensive study of IPv6 use to date.
"At its peak, IPv6 represented less than one hundredth of 1% of internet traffic" over the past year, Arbor Networks' Craig Labovitz writes in a summary of the findings, adding wryly: "This is somewhat equivalent to the allowed parts of contaminants in drinking water."
Arbor says it put together the study over the past year, working with the University of Michigan and almost 100 ISPs and content providers, including a quarter of the biggest ISPs in the US and Europe. It used commercial traffic probes to monitor about 2,400 peering and backbone routers and 278,000 customer and peering interfaces.
"We believe this is the largest study of IPv6 and internet traffic in general to date (by several orders of magnitude)," Labovitz says.
IPv6 is the successor to the current version of the internet's underlying protocol, IPv4. Its adoption is important because IPv4 can support only about four billion IP addresses and they are quickly running out. IPv6 will be able to support many trillions more (2 to the 128th power) and also offers advantages in security and network management.
Some experts say the supply of IPv4 addresses will run out in the next few years. Matthew Ford, a principal researcher with BT's Networks Research Centre, operates a website that counts down the days until IPv4 addresses are used up. Earlier this month, it predicted that the central registry of addresses will be exhausted in 904 days.
Few expect disaster to ensue. The Arbor report notes that IPv6 adoption is growing, albeit at a slow pace. Since July last year IPv6 traffic has grown by nearly a factor of five, to an average of 100Mbit/s per day. "Though not a landslide of adoption, it is still something," the report says.
What's more, there are already creative ways to get around the shortages, such as using network address translators, or NATs, which essentially allow many computers to share the same IP address. There are also many addresses that were allocated to organisations and are not being used.
That's why some, including Labovitz, expect companies to trade unused addresses with each other, on a black market if the activity isn't officially sanctioned. "I think an IPv4 market is inevitable," he says.
BT's Ford said he isn't surprised by the results, but he cautions that the figures may not be completely accurate. Arbor acknowledges that it did not distinguish between native and tunnelled IPv6 use, he notes, and the figures may also be skewed towards what's happening in the US, where many of Arbor Networks' customers are.
"The US has historically been quite sluggish, and most IPv6 research and implementation has been in Europe and Asia," says Ford, who previously chaired the IPv6 Cluster of the European Commission.
Nevertheless, the adoption has clearly been slow and the study should be a further wake-up call that widespread adoption of IPv6 needs to begin quickly, Ford says.
"Two or three years ago you could make the argument that [the exhaustion of IPv4 addresses] is far enough away that we don't need to make the investment," he says. But given that widespread adoption will take about two years to implement, "now is the time for large ISPs and content providers to begin their migration".
Arbor says money is the main reason for the delay. The US Department of Commerce has estimated it will cost US$25 billion (NZ$35 billion) for ISPs to upgrade to native IPv6. "This massive expense comes without the lure of additional revenue, since IPv6 offers diminishingly few incentives nor new competitive features to attract or upsell customers," Labovitz says.
Ford says enterprises may be among the earlier adopters because they can suffer the most from having to use IPv4.
"They can suffer problems through corporate mergers, because both parties might be using the same address space, or they find they have a lot of network address translators, which can make it challenging to deploy new applications. IPv6 helps both those problems," he says.