this site from google will tell you if your dns servers are ready for ipv6. if they arent then you could add googles public dns [8.8.8.8] or the opendns ip address [208.67.222.222]

see this post for instructions on how to add opendns to your mac
and this post for instructions on how to add google public dns to your mac

test-ipv6.com have another site and will give you lots of cool information on how you can start to get ipv6 aware.