Re: [Bridge] Problem with syslog in bridge(?) with ethernet broadcast packets with QinQ

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon, 18 Sep 2017 17:21:11 +0200
Andrés Pozo Muñoz <andres.pozom@gmail.com> wrote:

> 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

Where is the log message coming from? Could you change the printk into
a WARN_ON_ONCE and get backtrace? My guess is the firewall code doesn't
understand the additional tag.