For a couple of weeks, it seems that Google IPv6 measurements are heading down mainly for Europe. For example, here is a link to a presentation of the Google measurements for several European countries and USA. There is a clear drop in the last days/weeks for European countries but not for USA.
This includes a big drop for my country (BE) :-O and I have checked with all Belgian ISP and they have no explanation as for them 'business as usual'. Apnic also does not show such a big drop. So, I am guessing either a 'bug' in Google measurements infrastructure in Europe or could it be that the IPv6 latency to Google has increased a lot so that Happy Eyeball prefers IPv4? Recent measurement of dual-stack latency to www.google.com from several Belgian ISP gave 10% slower over IPv6. Any clue will be welcome -éric
