Re: periodic network disconnects (reason 'ip-config-unavailable')

[Pavel Simerda <psimerda redhat com>]

----- Original Message -----
> From: "Dan Williams" <dcbw redhat com>
> To: "Chuck Anderson" <cra WPI EDU>
> Cc: networkmanager-list gnome org
> Sent: Wednesday, May 1, 2013 10:30:15 PM
> Subject: Re: periodic network disconnects (reason 'ip-config-unavailable')
>
> On Wed, 2013-05-01 at 16:17 -0400, Chuck Anderson wrote:
> > On Mon, Apr 29, 2013 at 11:07:51AM -0500, Dan Williams wrote:
> > > On Sat, 2013-04-27 at 13:56 -0400, Chuck Anderson wrote:
> > > > On Fedora 18, I'm seeing periodic network disconnects with these
> > > > messages in the log:
> > > >
> > > > Apr 27 11:01:11 a NetworkManager[833]: <info> (wlan0): device state
> > > > change: activated -> failed (reason 'ip-config-unavailable') [100 120
> > > > 5]
> > > > Apr 27 11:01:11 a NetworkManager[833]: <warn> Activation (wlan0) failed
> > > > for connection 'Sanctuary 2.4GHz'
> > > > Apr 27 11:01:11 a NetworkManager[833]: <info> (wlan0): device state
> > > > change: failed -> disconnected (reason 'none') [120 30 0]
> > > > Apr 27 11:01:11 a NetworkManager[833]: <info> (wlan0): deactivating
> > > > device (reason 'none') [0]
> > > > Apr 27 11:01:11 a dbus-daemon[736]: dbus[736]: [system] Activating
> > > > service name='org.freedesktop.nm_dispatcher' (using servicehelper)
> > > >
> > > > What does reason 'ip-config-unavailable' mean and how can I
> > > > troubleshoot what is happening here?
> > > >
> > > > I do have IPv6 on this network and found this bug report, but that
> > > > appears to be for an older version and should be fixed in the version
> > > > in Fedora 18, NetworkManager-0.9.8.1-1.git20130327.fc18.x86_64:
> > >
> > > What are the messages just before that?  Is it IPv6 that's timing out?
> > > There should be some log messages about that.  You can also run NM with
> > > verbose IPv6 logging which might tell us more about what's going on.  So
> > > for now I'll suspect IPv6, and the issues there are that the router may
> > > not send advertisements quickly enough to prevent timed-out DNS servers.
> > >
> > > sudo dbus-send --system --print-reply
> > > --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager
> > > org.freedesktop.NetworkManager.SetLogging string:"debug" string:""
> > >
> > > grab the syslog output from that during a failure, then we'll see what
> > > the actual issue is and how to deal with it.
> >
> > This was caused by my router's radvd configuration being non-RFC
> > compliant.  I was troubleshooting my Android device's IPv6
> > connectivity so I had temporarily lowered the AdvDefaultLifetime,
> > AdvValidLifetime and AdvPreferredLifetime on radvd.conf.
> > Unfortunately, radvd lets you set these values to ones that violate
> > contraints required by RFC4861 (MUST be higher than the
> > MaxRtrAdvInterval).
> >
> > After fixing radvd.conf, NetworkManager is now behaving correctly.
>
> Ah, that explains it.  Good to know, thanks for the follow-up.  It might
> be a good idea to make NM complain (once) in the logs if this is the
> case for a particular network.

The problem is that MaxRtrAdvInterval is not published over the network. But I thought radvd was complaining 
and wouldn't start. If it is a recent version of radvd, it might deserve fixing. We'll be reworking the IPv6 
autoconfiguration using the libndp library and we can turn some of the messages to warnings/errors.

Cheers,

Pavel