[ovs-discuss] why is ovs for forwarding my packet?

[Flavio Leitner]

On Thu, Sep 18, 2014 at 10:21:40PM +0200, Ronald van der Pol wrote:
> On Thu, Sep 18, 2014 at 10:08:49 -0300, Flavio Leitner wrote:
> 
> > On Sat, Sep 13, 2014 at 11:40:21PM +0200, Ronald van der Pol wrote:
> > > On Fri, Sep 12, 2014 at 21:10:27 +0200, Ronald van der Pol wrote:
> > > 
> > > > This is my setup (part of OpenStack compute node):
> > > > 
> > > >    eth1    +---------+  phy-br-p2p2
> > > > A  --------+ br-p2p2 +---------------  B
> > > >            +---------+
> > > > 
> > > > The problem is this. B sends an ARP request to A, A answers with
> > > > an ARP reply. I see this reply packet on eth1, but not on phy-br-p2p2.
> > > > It is using VLAN 3810.
> > > 
> > > When I add eth1.3810 to br-p2p2 instead of eth1 and I set up a
> > > flow entry with action "mod_vlan_vid:3810,normal", it works.
> > > Don't quite understand yet what is different from forwarding
> > > tagged frames using eth1.
> > 
> > It sounds like the ARP reply is coming out of the VLAN 3810, so
> > the switch is just dropping it.
> 
> It seems the problem was that the server had an eth1.3810 interface.
> When we removed it, things started working normally. We are trying
> to confirm this in a more controlled test setup.

That would explain it. The ARP reply is delivered to that interface
because the vlan handling runs before OVS handling in the kernel.

fbl