IPv6/Google-over-IPv6について、ここに記述してください。 

On June 6th 2012, Google services will become generally available over IPv6 ...

https://www.google.com/intl/en/ipv6/

1. Google の実験

https://www.google.com/intl/en/ipv6/faq.html#request

2. Public DNS IPv6

https://developers.google.com/speed/public-dns/docs/using

http://jvnrss.ise.chuo-u.ac.jp/csn/index.cgi?p=Google+Public+DNS%A4%CEIPv6%C2%D0%B1%FE