Re: DNS lookup for git.postgresql.org

Bruce Momjian <bruce(at)momjian(dot)us> writes:
> On Tue, Jun 29, 2021 at 11:26:54PM -0400, Tom Lane wrote:
>> My buildfarm animals frequently complain of being unable to contact the
>> buildfarm server. Sometimes there's an identifiable problem at my end,
>> but usually not. A typical error looks like
>> error getting branches of interest: 500 Can't connect to buildfarm.postgresql.org:443 (Network is unreachable) at ./run_branches.pl line 199.

> OK, thanks. When no one said they saw similar behavior, I started
> digging deeper. It seems on Debian 10, bind/named uses IPv6 by default,
> and my ISP, Verison FIOS, doesn't support IPv6 yet; see:
> https://www.reddit.com/r/Fios/comments/li4ri7/does_fios_support_ipv6/

Oh, that's an interesting point. I have no IPv6 connectivity here either.
I'd figured out some time ago that with recent bind versions I need to use
named's "-4" option to prevent DNS lookup timeouts ... but now I see that
that doesn't stop it from returning IPv6 addresses. I wonder if the
failures occur when my animals try to use the buildfarm server's IPv6
address. I'll try the hack mentioned in the serverfault thread.

regards, tom lane