On Jul 9, 2015, at 9:02 PM, Matthew Kaufman <matthew@matthew.at<mailto:matthew@matthew.at>> wrote: On Jul 9, 2015, at 4:07 PM, Owen DeLong <owen@delong.com<mailto:owen@delong.com>> wrote: ... You are correct… In order for 20% of Google’s traffic to come from IPv6 connected devices, there would generally need to be more than 20% of all devices connected over IPv6. That doesn't follow at all. One guy who has v6 and really loves youtube can account for most of it. Matthew - That would be the case if the measurements of “IPv6 users” were based on traffic or packet counts, but Google’s measurements are based on specific pairs of HTTP connection attempts (one IPv4, and one IPv6) and the ratio of those which are IPv6 capable. The measurement methodology is documented in the Google research paper - <http://research.google.com/pubs/pub36240.html> I’ll also observe that APNIC has been conducting its own research via a different approach but achieved a rather similar measurement results for of IPv6 enabled users in the US - <http://labs.apnic.net/dists/v6dcc.html>. You can find more details on the approach used here <http://www.circleid.com/posts/20120625_measuring_ipv6_country_by_country> Both techniques indicate more than 20% of the US Internet users are connecting via IPv6. FYI, /John John Curran President and CEO ARIN