World IPv6 Day

The press is not doing a very good job of explaining the purpose of IPv6 day.

The problem with enabling IPv6 on web sites is that some implementations on desktop OSes did not handle fallback to IPv4 very well, so if a service published an IPv6 DNS record the client would try to use that even if it doesn't have IPv6 connectivity, causing the client to hang. This is supposed to have been fixed, but nobody knows if it's still a big problem or not, and it's one of the main reasons why most web sites have not enabled IPv6.

The point really has nothing to do with getting everyone to use IPv6 for a day, it's to make sure the web services can enable IPv6 and not break the existing IPv4 clients.

So happy IPv6 day. Don't feel bad if you're not using IPv6 today, just make sure nothing is broken when IPv6 is enabled on these sites.