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nyrikkiyesterday at 7:09 PM1 replyview on HN

In fact, 30 years later, I just had to add a IPv6 block on Ubuntu’s apt mirrors this week, because the aaaa record query has higher priority and was timing out on my CI, killing build times.

That behavior is due to the same politics mentioned above.

A few more pragmatic decisions, or at least empathetic guidance would have dramatically changed the acceptance of ipv6.


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Dagger2yesterday at 7:44 PM

AAAA records have lower priority than A records if you don't have a v6 address assigned on your system. (Link-locals don't count for this).

You would only see a timeout to an AAAA record if the connection attempt to the A record already failed. Some software (looking at you, apt-get) will only print the last connection failure instead of all of them, so you don't see the failure to connect to the A record. I've seen people blame v6 for this even though they don't have v6 and it's 100% caused by their v4 breaking.

Run `getent ahosts example.com` to see the order your system sorts addresses into. `wget example.com` (wget 1.x only though) is also nice, because it prints the addresses and tries to connect to them in turn, printing every error.

I mean... adding v6 is the right thing to do either way, but "AAAA is higher priority than A" isn't the reason.

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