IPv6 Makes Progress, but Much Work Remains

Six years after it brought together thousands of ISPs and website operators together to participate in World IPv6 Launch by permanently enabling IPv6, the Internet Society says the new internet protocol has made dramatic progress.

Today, more than 25% of all internet-connected networks advertise IPv6 connectivity, according to the nonprofit's State of IPv6 Deployment 2018 report issued Wednesday. Major network operators such as T-Mobile in the US and British Sky Broadcasting have "massively deployed" IPv6 at 93% and 86% respectively, and nearly half a billion people use IPv6 among the top 15 ISPs combined, ISOC said. Comcast has the second-most IPv6 users with 36 million, after India's Reliance Jio with 237 million.

Eighty percent of smartphones in the US on major cellular network operators use IPv6, up from under 40% three years ago, according to ISOC. Twenty-eight percent of the Alexa top 1,000 websites are IPv6-enabled. IPv6 has moved from the early adoption stage of deployment into the "early majority" phase, the group asserted.

Despite the progress, enterprise networks remain "the elephant in the room" when it comes to IPv6 adoption, according to the report. If nearly 26% of network advertise IPv6 prefixes, "74% do not, and those are likely to be enterprise networks," ISOC said.

Businesses have a lot of incentives to migrate to IPv6, including the cost of IPv4 addresses, the group said. Cloud hosting providers are starting to charge for IPv4 addresses, but keeping IPv6 services free from additional charges for address space.

"Increasingly, IPv4 is an unnecessary cost, and speculative asset. An IT department or CIO that is faced with purchasing IPv4 addresses has reason to ask whether the expense is worth the value. The short answer is that it increasingly is not," ISOC said. "Even when not faced with that decision, the company would do better, in the long term, to sell the address space it has and use the money to fund IPv6 deployment, connecting to an upstream ISP that will use translation mechanisms to connect to remaining IPv4-only content."

The overall upbeat report, which ISOC compiled with data from Akamai Technologies, the Asia-Pacific Network Information Centre (APNIC) regional registry, Facebook, and Google, contrasts with a May 21 blog post from APNIC, which describes IPv6 growth as appearing to stall this year.

"A major change in the IPv6 deployment picture occurred over the two-and-a-half-year period from the start of 2015 to mid-2017. Over that period the level of IPv6 adoption rose from 3% to 15%, and the majority of that rise occurred in the first half of 2017. By the end of 2017, the level of IPv6 deployment was measured at some 18% of the Internet, but there has been no significant further movement in that number across the first four months of 2018," wrote Geoff Huston, APNIC chief scientist.

"Just four months is probably an insufficient period to justify an assertion that IPv6 deployment has stalled, but the hiatus in the growth of the use of IPv6 is certainly a source of some concern," he added.

In examining the reason for the slowed growth, Huston said the internet today operates as a client-server network in which clients do no need a persistent network-wide identity.

"We have positioned IP addresses in a different role, and no longer need to associate a unique public IP address with every connected endpoint. Address sharing technologies have allowed us to grow the pool of connected devices far beyond the number of unique addresses in the protocol," Huston wrote.

"How far can this client/server model grow while relying on IPv4?" he added. "How many devices can we cram into the IPv4 internet before we break it?"