Counting IPv4 and IPv6 hosts

This page contains a very small (1x1 pixel) transparent image which is:
  1. first fetched over IPv4
  2. the server remembers the IPv4 client address and redirect to another image (passing the IPv4 + ID)
  3. this second image is reachable only over IPv6 through the numerical IPv6 address (to force the use of teredo)
  4. the server remembers the IPv6 client address as well as the IPv4 address and sends the actual small image
This allows to get some statistics. If you want to see the 1x1 transparent pixel image, click here.
Feel free to add this counter to your page by adding the following HTML tag on any of your web page (even if hosted on an IPv4 only server):
<img src="http://ipv6stats.noroutetohost.net/image4.php" width="1" height="1" border="none">

Written by Eric Vyncke (evyncke@cisco.com) August 2008