Re: exim, local resolver, host name lookups and IPv6
* "Bernhard R. Link"
| * Marc Haber <mh+debian-devel@zugschlus.de> [080412 10:30]:
| > >I think the main problem is that Debian is by default setting up those
| > >ipv6 stuff into the interface even when you are in an pure ipv4
| > >environment. That way exim4 cannot do anything to avoid ipv6 stuff
| > >and evil things like this can happen.
| >
| > Another process on the local system might actually use IPv6 on the
| > local links, so I'd vouch for tweaking the system (or exim) to not
| > break if IPv6 is enabled but not fully connected.
|
| Yes, that might even be better. Sadly while getaddrinfo(3) has
| AI_ADDRCONFIG, it says "IPv6 addresses are only returned if the local
| system has at least one IPv6 address configured". (Dunno if something
| like "has a working ipv6 setup" instead would be properly detectable
| by libc).
If «has a working ipv6 setup» means «has a address with scope better
than $value», then yes, that's easy. See my other post to this
thread. I think «has at least one IPv6 address configured» should
mean «has at least one IPv6 address which may be in DNS configured».
Yes, this probably breaks NAT-PT, this probably also breaks for people
who want to talk to services on localhost using IPv6 (and doesn't
otherwise have IPv6 configured) as well as people who put link-local
addresses into DNS. Don't do that, then. IMNSHO.
--
Tollef Fog Heen
UNIX is user friendly, it's just picky about who its friends are
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