Problem with OpenStack Getting Started Guide

[Daniel P. Berrange]

On Tue, Jan 03, 2012 at 09:02:17PM +0000, Mark McLoughlin wrote:
> On Tue, 2012-01-03 at 18:35 +0000, Daniel P. Berrange wrote:
> > On Tue, Jan 03, 2012 at 11:29:40AM -0700, Steven Dake wrote:
> > > On 01/03/2012 05:32 AM, Mark McLoughlin wrote:
> > > > On Fri, 2011-12-23 at 13:16 -0700, Steven Dake wrote:
> > > >> Killing the first VM that was started (which has a MAC address equal to
> > > >> the br0) will cause deletion of vnet0 and cause the bridge driver to
> > > >> flush the arp table and choose a new bridge interface.  This results in
> > > >> disconnection of the remaining VM for 30-60 seconds.  
> > > > 
> > > > What exactly is happening during this time? The guest's routing table is
> > > > configured with the host as its gateway and it has a stale ARP cache
> > > > entry for the host?
> > > > 
> > > > Cheers,
> > > > Mark.
> > > > 
> > > 
> > > br0 adopts the mac address of the first interface added to it.  If the
> > > first interface added to it is removed, br0 finds a new mac address from
> > > the "next" interface in the bridge.  When the mac address is removed,
> > > the arp table is flushed for 30-60 seconds.
> 
> You mean the host kernel arp table is empty for 30-60 seconds? or ...?
> 
> A stale arp cache in the guest, I can understand. Anything else smells
> like a bug.

Yes, the guest arp table that contains outdated entries after the bridge
reconfigures its MAC addr.

Regards,
Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|