Problem with syslog in bridge(?) with ethernet broadcast packets with QinQ

[Andrés Pozo Muñoz <andres.pozom@xxxxxxxxx>]

Hi all,

I'm facing some problem with ethernet multicast traffic and QinQ
(802.3q in both tags) in -apparently- a bridge in Ubuntu 16.04
(4.12.0-041200-generic).

My set up is the following:
+-----------+
|     VM    |
+-----+-----+
      |
      | tag 55
+---------+------------+
|        OVS           |
+-----------+----------+
                | veth3.9
veth3   +  |
     +--+
     | veth2
+-------+----------+
|       BRIDGE     |
+-------+----------+
     |
     |
+-------+----------+
|      ens11f1     |
+------------------+


I am setting the inner tag with OVS and the outer tag with a vlan type veth.
The problem I have is that every packet sent from the VM to Ethernet
broadcast addresses (33:33:xx:xx:xx:xx) generates a "IPv6 header not
found" entry in syslog.

If I generate a 'ens11f1.9' interface and remove the BRIDGE, the log
entry dissapears.

Some questions:
* Is there any problem with these packets (ethernet multicast with
QinQ) in bridges?
* Is there any configuration I should change for the problem to dissapear?

Thanks in advance for your help! Any hint about what could be
generating those logs is appreciated.

Regards,
Andrés Pozo