Connectivity to an IPv6-only site

Jason Fesler jfesler at
Sun Apr 25 12:11:26 CDT 2010

> Its a shame there is not a pair of images on this site - one originated 
> from a v4 only box, one a v6 only box.  The img src= could point to the

I've been working on something in this direction this past week, that is 
primarilly for user facing debugging purposes (versus for a content 

will tell the user what to expect, after having them try a combination 
of image fetches  (ipv4, ipv6, dual stack, ipv4 literal, ipv6 literal).
It does each set of images 2-3 times (minimum is 2; a third pass is done 
if they go quick enough) and gets the "best" time of each type of fetch.

Based on the successes and failures, and the times, it tries to give a 
straight-English explanation to the end user on what the future internet 
might look for them, based on their *current* internet service / OS / 
browser.  Lastly, it posts the results back to my server, along with the 
user agent string, in case there are any trends that can be learned.

On my todo list is to have it detect the case where the user timed out 
trying to reach the IPv6 and dual stack names; and ask the user for more 
details (ie, netstat -nr and ifconfig/ipconfig).

Feedback welcome, preferably off-list.  If there's a desire for me to 
summarize, or anything earth shattering, I'll followup on-list.

I'm especially interested in people who've allowed utorrent to enable 
ipv6 to send me their results. :)

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