In the second half of 2013, many of the metrics we at Akamai use to track IPv6 adoption have doubled. This is in large part due to increased adoption by residential broadband networks in the U.S. and Germany. Over the course of a given week, we now observe more than 600 million unique IPv6 addresses per week, as opposed to 200 to 300 million in June 2013. We are also serving over 20 billion IPv6 requests per day, double the 10 billion per day delivered six months ago.
Since IPv6 adoption has been viewed as "just around the corner" for years, even many people involved in running Internet infrastructure make the assumption that IPv6 adoption is still lost in the noise. The accelerating growth of IPv6 makes this a dangerous assumption, as adoption has rapidly picked up in some important areas.
IT organizations, content providers, networks, and software vendors without an active IPv6 rollout program may find themselves caught unawares in a situation where significant markets may have double-digit percentages of IPv6 connectivity by later this year.
As of mid-December 2013, more than 5% of the requests to dual-stacked sites were delivered over IPv6 to users in the U.S., Belgium, Germany, Luxembourg, Peru, Romania, and Switzerland. If we exclude devices and browsers that don't aggressively support IPv6, we get a better perspective of IPv6 penetration into networks and see all of these numbers rise to include more than 11% of requests.
It is likely that this adoption is likely to grow further over the coming months as networks continue to roll out IPv6.
IPv6 user distribution
To understand where growth is coming from across a number of dimensions, we analyzed more than 300 billion requests against dual-stacked sites (just a sample of the requests arriving during a 24-hour period on Wednesday, December 11, 2013) and compared them to the requests analyzed for the 24-hour period six months earlier on Wednesday, June 12, 2013. Some of the results of this analysis follow.
For background, a dual-stacked site is one that is available over both IPv4 and IPv6, and is the only viable transition mechanism for content due to the lack of direct connectivity between the IPv4 Internet and the IPv6 Internet.
Note that some of these statistics may understate the level of access to IPv6 connectivity. In particular, we are measuring the percentage of IPv6 requests relative to the total requests to dual-stacked sites. Devices pull these percentages down when they have access to IPv6 connectivity that they do not consistently use.
To get closer to measuring the degree of access to IPv6 connectivity, we show some of these percentages separately when filtering to only requests from some of those devices and clients that are more likely to use IPv6 when it is available: Apple iOS 7, Android 4.1 and later, Blackberry 10, Mac OS X 10.7 and later with Chrome and FireFox (but not Safari), Microsoft Windows Vista and later, Windows Phone 8, and the XBox One console.
IPv6 by geography
With major carriers actively rolling out IPv6 across their networks, the U.S. and Germany have taken the lead in IPv6 traffic volume as delivered by Akamai. The percentage of IPv6 requests to dual-stacked sites in the U.S. has risen 32 times in two years, from a meager 0.2% in November 2011 to 6.4% in December 2013. Looking at select devices and clients more likely to use IPv6 when available, the number was 11% in December 2013.
Germany, Peru, and Luxembourg also saw IPv6 as a percentage of requests to dual-stacked sites double to more than 5% in the six months from June to December 2013 (with all more than 10% when filtering to select devices and clients). The difference between the percentage of IPv6 for all clients versus select clients may be a function of how many older clients with limited IPv6 support (such as Windows XP and older mobile operating systems) exist within each country.
Some of the largest networks in some of the world's largest economies are actively in the process of rolling out IPv6 to their subscriber bases this year. IPv6 is no longer just for universities and research labs.
Companies without a plan to make their content available over IPv6 and networks without plans to roll IPv6 out to their end users may be caught off guard soon if IPv6 growth continues at its current rate. It is only a matter of time (although perhaps still a few years) before some networks look to deploy IPv6-only connectivity as a cost-saving and simplification measure.