Estimation of IPv6 Brokenness

Using a technique first proposed by Tore Anderson (and with Tore's help), this page contains data about IPv6 brokenness, this is the risk of losing users/customers when a web site goes dual-stack and publishes both a A and a AAAA for the same URL.

The technique is to embed in the original IPv4-only page an IFRAME with three very small (1x1 pixel) transparent images which are:

  1. IPv4-only: fetched over IPv4 explicitely (from a FQDN with A only)
  2. Dual-stack: fetched over IPv4 or IPv6 (from a FQDN with A and AAAA, so, the client decides which protocol statck)
  3. IPv6-only: fetched over IPv6 explicitely (from a FQDN with AAAA)
By counting how many images were fetched over IPv4-only and comparing with the dual-stack fetches, we can measure:
DateSample sizeIPv4-onlyDual-stackIPv6-onlyIPv6 brokennessIPv6 availabilityIPv6 preferred
Since ever
13675968874758797872458870.56 %17.98 %79.9 %
Since last month
3028151715154650.07 %15.36 %74.62 %
Since last week
54624224486-0.37 %15.75 %61.63 %
Since yesterday
93373822-1.08 %23.66 %90.91 %

Please note that the data is processing once per European night, so, data is always delayed by one day.

Broken user-agents are also collected, you can have a look; as well as broken ASN, you can have a look.

What about my own web site?

Feel free to add this IPv6 brokenness to your existing IPv4-only web site by adding the following HTML tag on any of your web page
<iframe src="" width="1" height="1" frameborder="0"></iframe>
Of course, you have to replace by the FQDN of your web site ;-)

Once, done, you can go to this page to see brokenness result for your site (computed daily around midnight CET):

Written by Eric Vyncke ( October 2010