Re: ssh issue that I don't understand

On Mon, Jul 06, 2026 at 10:41:36AM -0400, Greg Wooledge wrote:
> I'm slowly being convinced that name resolution is the real problem here.

I agree, but in a much simpler way.

OP has been repeatedly asked to confirm whether the IPv6 address in DNS
is actually pointing at the same host as the IPv4 address, but has not
yet confirmed.

Someone (Vincent?) pointed out that the whois records for the two IP
addresses show very different entities. Still feasible for it to be the
same host, but looking suspicious by now. But for me, when I traceroute
to the IPv4 address it's about 5.6ms from me, whereas the IPv6 address is
about 0.6ms from me.

The reverse DNS of the IPv6 address is caracal.mythic-beasts.com., which
bears nbo relation to OP and is a well-known hosting outfit in UK.

So my conclusion is that two two addresses are in very different parts
of the Internet. Not 100% confirmed since one can easily introduce weird
routing and fake delays, but that would require some weird scheme, so
the most likely answer is it's simply a wrong IPv6 address.

The reason why it always goes wrong when using host name is that Linux
prefers to use IPv6 addresses when it has both.

Thanks,
Andy