Re: Network problems in gnome-session

[Dan Williams <dcbw redhat com>]

On Fri, 2007-03-02 at 22:34 -0500, Ray Strode wrote:
> Hi,
> 
> > So, do you think that it's a configuration problem on my side or
> > actually a bug in gnome-session? I still think it's the latter.
> I don't really know what's going on, but I'm guessing it's either a
> bug in the NetworkManager backend for your distro, or a bug in libc.
> 
> I have these vague memories of apps taking ~30 seconds to recognized
> network changes after early versions of NetworkManager switched
> networks and it ended up being some glibc interaction that I don't
> remember the details of.

glibc doesn't reload /etc/resolv.conf unless the app specifically
reloads the resolver (using _res_init()), or unless something like a
caching nameserver is used.  The 30s thing that Ray is talking about is
when an app is in the middle of a DNS query, and the network switches
and rewrites resolv.conf.  The app won't notice the change until the
in-progress query times out.

Mozilla tries to work around this by calling _res_init() a lot, but that
doesn't work all the time.

The only foolproof way to not experience the /etc/resolv.conf update
issue is using a caching nameserver.

Dan