The 8th June 2011 could be an interesting day for the internet as some of the big websites and services do an IPv6 test day.
If you're interested in testing just how ready your ISP is, try this link.When the clock hits midnight on Wednesday, June 8 UTC, World IPv6 day begins. Many Web destinations—including the four most popular (Google, Facebook, YouTube, and Yahoo)—will become reachable over IPv6 for 24 hours.
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I'm currently connected via Cell C and it tests out fine except for their DNS resolver which doesn't pass muster. Fortunately according to the technical blurb on this particular test:
This is a test of your ISP's resolver (instead of a test of your host). If this test passes, your DNS server (often run by your ISP) is capable of reaching IPV6-only DNS authoritative servers on the Internet. This is not critical (at this time) for you to reach sites via IPv6.