[Lxc-users] lxc container messing with hosts networking

[Serge Hallyn]

Quoting arkaitzj at gmail.com (arkaitzj at gmail.com):
> On Mon, May 16, 2011 at 6:11 PM, Serge Hallyn <serge.hallyn at canonical.com>wrote:
> 
> > Quoting arkaitzj at gmail.com (arkaitzj at gmail.com):
> > > Well, as I said it has to be something from the setup I do because I keep
> > > having those problems even with laptop(natty)->kvm(natty)->host(natty)
> > >
> > > I recorded this screencast that shows the issue:
> > > http://www.screencast-o-matic.com/watch/cXhD2hbLM
> >
> > Got it!
> >
> > It's the user networking.  When I start a debian vm with libvirt (using the
> > default tap interfaces) I don't get the hang.  When I start the same vm by
> > hand using -net user the way you do in your script, I do get the hang.
> >
> 
> Nice!  but I don't believe it is just a kvm issue if you are suggesting
> this, as it happened to me on a standard debian on a laptop over a wireless
> link, br0 to wlan0 etc... and had same hang.

AFAIK you can't bridge wlan0, can you?  Am I wrong about that, or do
you mean that you forwarded br0 to wlan0 using iptables?  If the latter,
then note that in that case you no longer have a physical NIC attached
to the bridge, so we might be back to the issue of the bridge changing
MAC addresses when virtual NICs are attached.

> Any ideas what could be causing it? it has to be something on the host
> system.

I think my reproduction of it is an issue with the '-net user' driver.
I haven't looked at the code for that.  My guess would be that the
bare metal reproduction of it which you mention above was due to a
different cause.

I certainly could be wrong about that.

-serge