Re: Anybody Using IPv6?

"Carlos E. R." <robin_listas@es.invalid> wrote:

On 2025-05-21 13:16, Marc Haber wrote:

I think that the local resolver should² also refrain from asking for
AAAA records if the local system doesn't have IPv6, but I don't know
whether this special-case handling is implemented at all. And I'm too
lazy to look that up.
>
But all this needs to be taken into account before someone can comment
about speed of one IP protocol compared to the other on a level that
is beyond passing myths.

>
It just is a perceived fact. On some machines, if an application gets
back from the system a list of addresses to try, and tries IPv6 first
when there is no actual IPv6 internet connectivity, there is a small
delay waiting for the request to fail, and then try the next address in
the list.

 pcap/strace or it didn't happen.
 Please note that _broken_ IPv6, for example when the router announces
an IPv6 but the network doesn't return a host unreachable ICMPv6
message from the place where connectivity is missing, will cause an
IPv6-enabled application to wait for the time out. But that is an
error in the _network_ setup, and should not happen in the case where
the end system (the one with the application running) has v6 enabled
on a non-v6-enabled network.