[ovs-dev] mpls and vlan qinq

[Jesse Gross]

On Mon, Mar 19, 2012 at 2:14 PM,  <KerurR at telekom.de> wrote:
> When kernel >= 2.6.37 and vlan_tpid = 0x88a8, in function netdev_send,
> __vlan_put_tag present in OVS tree is not executed since
> dev_supports_vlan_tx returns true. It goes through the path of
> dev_queue_xmit which eventually calls __vlan_put_tag present in the kernel
> source tree. Need some inputs here. For kernel < 2.6.37, things work fine. I
> have verified it on 2.6.32 Centos 6.2 system.

Are you actually seeing a problem?  What you are describing sounds
like correct behavior - OVS is just emulating behavior of new kernels
in that code vport-netdev.c, so on those kernels we don't need to do
it and dev_queue_xmit() can take care of it if necessary.

Note that __vlan_put_tag() always uses a TPID of 0x8100, so you can't
use it for other values.