[ovs-dev] [PATCH] FAQ: Explain why VMs on a VLAN can't access the Internet.

[Ben Pfaff]

On Fri, Mar 22, 2013 at 04:17:03PM +0000, Kyle Mestery (kmestery) wrote:
> 
> On Mar 21, 2013, at 5:26 PM, Ben Pfaff <blp at nicira.com> wrote:
> 
> > Signed-off-by: Ben Pfaff <blp at nicira.com>
> > ---
> > FAQ |   14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> > 
> > diff --git a/FAQ b/FAQ
> > index 90d0003..d9224fa 100644
> > --- a/FAQ
> > +++ b/FAQ
> > @@ -714,6 +714,20 @@ A: It is to be expected that the VMs can't access each other.  VLANs
> >    the machines you are trying to access are not on VLAN 9 (or 10) and
> >    that the Internet is not available on VLAN 9 (or 10).
> > 
> > +Q: I added a pair of VMs on the same VLAN, like this:
> > +
> > +       ovs-vsctl add-br br0
> > +       ovs-vsctl add-port br0 eth0
> > +       ovs-vsctl add-port br0 tap0 tag=9
> > +       ovs-vsctl add-port br0 tap1 tag=9
> > +
> > +    The VMs can access each other, but not the external network or the
> > +    Internet.
> > +
> > +A: It seems likely that the machines you are trying to access in the
> > +   external network are not on VLAN 9 and that the Internet is not
> > +   available on VLAN 9.
> > +
> 
> Maybe add this after what you have:
> 
> Ensure VLAN 9 is setup on the upstream switch port which eth0
> is connected to, either as an access VLAN or as an allowed trunk
> VLAN.
> 
> With that, looks good to me.
> 
> Acked-by: Kyle Mestery <kmestery at cisco.com>

Doesn't it need to be configured as a trunk on the upstream switch?  OVS
will send the packets from the VMs out eth0 with 802.1Q headers with
this configuration.