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Re: Happy Eyeballs doesn't seem to work with c-ares when IPv6 name servers on top of the name server list don't respond

From: Daniel Stenberg via curl-library <>
Date: Thu, 25 Nov 2021 15:01:19 +0100 (CET)

On Thu, 25 Nov 2021, Dmitry Karpov via curl-library wrote:

> IPv6 server1 <not responding>
> IPv6 server2 <not responding>
> IPv4 server1 <good>

It just struck me: did you mean "IPv6" vs "IPV4" here as servers that respond
with A and AAAA records, or are they simply servers you access over IPv4 and
IPv6 and they can both respond with any type of records?

Because if the latter, then it sounds like a c-ares bug, but in the earlier
case I don't really see an easy solution other than for your application to
somehow detect this and drop IPv6 use going forward.

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Received on 2021-11-25