Posts Tagged ‘DNS’

Why is this web site reachable via IPv4 only?

You’re right, there are no AAAA records, intentionally. A percentage of users are unable to browse sites that are dual-stack. If the users can’t connect, then they can’t be told they have a problem. This is a big problem facing content providers today; of which, I work at one for my $dayjob. As such, the main test page requires IPv4 (either native or translated).
At some point, when the percentage of “broken” users has gone significantly down, I’ll consider making dual-stack..
Q: How do I test my IPv6-only host
If you ask that question, chances are you don’t need this site. However, if you really want to, visit with your IPv6-only host.
Q: What do you mean by broken?
A percentage of users today have IPv6 enabled, but are either using a public tunnel that is currently giving poor performance; or otherwise have a route that is installed but broken or suboptimal. However, because they have a route at all, in many cases the address selection algorithm of RFC3484 will pick using it, and trying to use this broken route. It can take towards 75+ seconds before the browser gives up!
From the perspective of a user with these conditions, a web site offering both A and AAAA DNS records (ie, “dual stack”) will appear to time out; and the user will move on to another site that offers a similar product. This is the quandary content providers have.
If we detect that you will have problems reaching dual-stack web sites, we recommend you see the Broken User FAQ. It provides several steps to try and identify your root cause for being broken; and barring that, what you can do to disable IPv6 until your ISP offers native IPv6 connectivity.
Q: Why did your stats say you already have IPv6-only users?
They went to .
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