[ovs-discuss] br0 dropping VLAN 0 packets and internal port br0

[Dietrich, Stefan]

Hello,

I just started playing with Open vSwitch and some questions started coming up.

My setup:
- 1x Scientific Linux 6.1 x64 KVM hypervisor
- OpenNebula 3.2.1 creating virtual machines, Open vSwitch enabled
- Open vSwitch 1.4.0 build from source with brcompat enabled
- Two interfaces eth0 and eth1 configured as bond0 with VLANs 123 and
567 allowed.

To access my hypervisor again with an ip address, I created one fake
bridge 'mgmt0' with the tag 567. Via ifconfig I added the ip address.
This is working so far without problems.

The virtual machines should run on VLAN 123. The vnet ports were created
by OpenNebula, when the virtual machine is launched. The virtual
machines have a working network connectivity to the outside world.

But I am getting this error very often in my ovs-vswitchd.log:
May 11 09:57:27|03042|ofproto_dpif|WARN|bridge br0: dropping VLAN 0
packet received on port bond0 not configured for trunking VLAN 0

The documentation says, that this is untagged traffic, right?
Should there be really untagged traffic?

My other question is, why do I have an internal port br0 (see output below)?
I can ifconfig this br0 port, but what VLAN is it using?

Regards,
Stefan

ovs-vsctl show
40ff7447-5c7e-48fb-ae49-12b8c6720468
Bridge "br0"
Port "vnet4"
tag: 123
Interface "vnet4"
Port "vnet3"
tag: 123
Interface "vnet3"
Port "vnet2"
tag: 123
Interface "vnet2"
Port "vnet9"
tag: 123
Interface "vnet9"
Port "vnet5"
tag: 123
Interface "vnet5"
Port "mgmt0"
tag: 567
Interface "mgmt0"
type: internal
Port "vnet6"
tag: 123
Interface "vnet6"
Port "vnet8"
tag: 123
Interface "vnet8"
Port "vnet0"
tag: 123
Interface "vnet0"
Port "vnet1"
tag: 123
Interface "vnet1"
Port "br0"
Interface "br0"
type: internal
Port "bond0"
trunks: [123, 567]
Interface "eth1"
Interface "eth0"
Port "vnet7"
tag: 123
Interface "vnet7"
ovs_version: "1.4.0"

[Ben Pfaff]

Post by Dietrich, Stefan
May 11 09:57:27|03042|ofproto_dpif|WARN|bridge br0: dropping VLAN 0
packet received on port bond0 not configured for trunking VLAN 0
The documentation says, that this is untagged traffic, right?
Should there be really untagged traffic?

Your bond0 is connected to eth0 and eth1, presumably physical Ethernet
ports. You will have to tell me whether there untagged traffic should
ever be received on that port. I can't tell you because I don't know
what else is connected to those ports through an upstream switch.

Post by Dietrich, Stefan
My other question is, why do I have an internal port br0 (see output below)?
I can ifconfig this br0 port, but what VLAN is it using?

There's always an internal port with the same name as the bridge. The
rules for its VLAN configuration are the same as for other ports. In
this case, it's a trunk port for all VLANs.

[Dietrich, Stefan]

Post by Ben Pfaff

Post by Dietrich, Stefan
May 11 09:57:27|03042|ofproto_dpif|WARN|bridge br0: dropping VLAN 0
packet received on port bond0 not configured for trunking VLAN 0
The documentation says, that this is untagged traffic, right?
Should there be really untagged traffic?

Your bond0 is connected to eth0 and eth1, presumably physical Ethernet
ports. You will have to tell me whether there untagged traffic should
ever be received on that port. I can't tell you because I don't know
what else is connected to those ports through an upstream switch.

Untagged traffic should not be allowed. I run tcpdump on eth0, set up
the filter to filter tagged traffic and the only packages left are just
spanning tree packages. So this should be ok (should have checked first
before asking).

Post by Ben Pfaff

Post by Dietrich, Stefan
My other question is, why do I have an internal port br0 (see output below)?
I can ifconfig this br0 port, but what VLAN is it using?

There's always an internal port with the same name as the bridge. The
rules for its VLAN configuration are the same as for other ports. In
this case, it's a trunk port for all VLANs.

Ah ok, questions solved.
Thank you very much for your help!

Regards,
Stefan