On 21/11/2012, at 3:05 AM, Patrick W. Gilmore <patr...@ianai.net> wrote:
> On Nov 20, 2012, at 08:45 , Owen DeLong <o...@delong.com> wrote: > >> It is entirely possible that Google's numbers are artificially low for a >> number >> of reasons. > > AMS-IX publishes stats too: > <https://stats.ams-ix.net/sflow/> > > This is probably a better view of overall percentage on the Internet than a > specific company's content. It shows order of 0.5%. > > Why do you think Google's numbers are lower than the real total? It depends on what you are trying to measure and how you are measuring it. I don't know Google's methodology, but lets say its a simple form of the experiment: "When presented with a dual stack object what percentage of users prefer to retrieve that object using IPv6 as compared to IPv4?" Up so a year or so ago if a browser had access to IPv6 and IPv4 it would first attempt to connect using IPv6 and if the connection failed then it timed out and then tried to use IPv4. So the experiment would be roughly commensurate with measuring working IPv6 systems on end sites connected to workin ipv6 access networks of one sort or another. More recently some browsers (Safari on Mac OSX, Chrome, Firefox with config settings enabled) have adopted a different strategy and when presented with a dual stack object some clients may end up trying the connection using IPv4 first and then fall back to IPv6 if IPv4 fails or times out. If the experiment simply counts the percent of clients who prefer to connect using IPv6 in a Dual Stack scenario, then some of these users running more recent versions of the browser will not be counted. There are ways to compensate for this, including running a series of tests, and this form of approach is described at http://labs.apnic.net/measureipv6/ I personally have no knowledge if the numbers published by Google reflect the "prefers to use IPv6 in dual stack mode" or "is capable of using IPv6 (by virtue of being able to retrieve a IPv6 only object)" These days the second number is larger than the first. Geoff
