Broken DNS client resolvers (Was: Dealing with filtered 6to4 clients)

[Rémi Denis-Courmont]

On Tue, 27 Oct 2009 13:39:42 +0100, Jeroen Massar <jeroen at unfix.org> wrote:
> As an excellent example look at:
> https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/417757

Hmm well, I suspect the problem is rather along the line of glibc depending
on the little-known and hence under-used AI_ADDRCONFIG flag for correct
RFC3484 operation. With that flag, it will only look quad-A records up if
there is one (non-link-local) IPv6 address configured - in this case, it is
reasonable to assume DNS works correctly, especially as Linux distros don't
do "automatic" 6to4 setup by default.

Whether it's a glibc or a many-applications bug is debatable.

-- 
Rémi Denis-Courmont