In an earlier post I cast aspersions on how T-Mobile US was dealing with IPv6. I wish to correct that now.
The debugging took me a little time as IPv6 was not working on my home cable Internet service. Cox Cable claimed IPv6 was enabled and should work. And my router claimed that it supported IPv6. After some back and forth, I found that a firmware upgrade on my router was required. Once upgraded, all the devices in the house that support IPv6 claimed they were given routable addresses and they were able access most IPv6 accessible sites.
But they were not able to access my server. If both Cox and T-Mobile have trouble routing to my server the issue seemed likely to be on the server side. And having a test case other than T-Mobile was a big step forward as enabling data on my mobile phone is expensive and I wanted test cases I could run more easily from a “real” computer.
Once T-Mobile was off the hook, it was a matter of finding some IPv6 test sites located around the world that the hosting company could use to confirm there was an issue with their setup. I was able to find a couple of test sites that had the same routing issue as Cox Communications and T-Mobile US and with that information the hosting tech support people were eventually able to fix their routing issue.
With that squared away, I can now access email, calendars, etc. from my server via IPv6 from both my home and from my phone. No need to force a fall back to IPv4.