inn2: IPv6 quirks

[Klaus Alexander Seistrup]

Dennis Kaarsemaker <dennis at kaarsemaker.net> wrote:

> Why does gethostbyname() or whatever call is used return an ipv6
> address on an ipv4-only host? I don't see this as a quirk in INN, if it
> get's an ipv6 address, it should be able to use it. If it has no ipv6
> interface, why does it get an ipv6 address?

I have no idea about the inner workings of INN (or gethostbyname()),
but I have experienced the situation I described for two of my [IPv4
only] news peers (my own newsbox is IPv6-enabled and advertises both A
and AAAA records).

It *could* be that the "IPv4 only" hosts in fact does have IPv6
enabled in the kernel, thus giving the lo interface an ::1 address,
and a pseudo-IPv6 address to ethX, but that there is no IPv6 route to
the outside world.  Who knows...

It's not only INN, though, I have seen the same for ntpd.

However, browsers like Mozilla and Konqueror falls back to using IPv4
if IPv6 fails, and I think it would be prudent of INN and ntpd to do
the same if they fail with "no route to host" or "network unreachable"
because they're trying the dead end.

Cheers,

-- 
Klaus Alexander Seistrup
SubZeroNet · Copenhagen · Denmark
http://magnetic-ink.dk/