A few hours ago Opera released the final of Opera 10.50. With this release Opera has fixed a big IPv6 problem.
In previous releases the Opera webbrowser unconditionally preferred IPv6 over IPv4, even if the IPv6 connection was for example a Terredo connection. With this new release Opera complies with RFC3484 and only prefers IPv6 if that connection is native.

The effect that this bug had has been made available by Tore Anderson by including 1×1 pixels over dual stack and IPv4-only on a high traffic website located in Norway. In his latest Februari report there is a IPv6 brokenis of 0.094% and if you exclude Opera it’s 0.029%. Reports are available for October, November, December, Januari and Februari.

Some websites, including Google, don’t offer a AAAA DNS record because of this small portion of customers (but many users if you are a large content provider) they would lose when introducing a AAAA record. Instead they offer something like ipv6.domain.com or in the case of Google set up a whitelist program.  Opera, like most browser, offers upgrades without intervention of the user so this new release should be adopted soon by Opera users. Let’s hope this will inspire content providers to include AAAA records without any limitations. The browsers are ready.

Thanks to Tore Anderson for making these reports available.