Re: [Qemu-discuss] qemu guests using 802.1q vlans bridged on host

[Tony Su]

If you're configuring the all your "hundreds" of guests to connect to
the same VLAN, then you should able to simply configure all guests to
connect to the same working bridge device without further
configuration.

You're surely not trying to configure hundreds of individual vlans,
separate ones for each guest?

Tony

On Thu, Aug 22, 2013 at 10:04 AM, Stephan von Krawczynski
<address@hidden> wrote:
> Hello Tony,
>
> thank you for answering, my comments are inline. Just as an additional hint to
> what I've tested so far. Since I found vlan bridging not working I configured
> the vlan on the host and put that interface to a bridge and over to a virtio
> device (non-vlan-tagged) in the guest. As you might expect this works
> perfectly. Unfortunately it is not useable for me, because if you want several
> hundred vlans to several guests you will end up configuring hundreds of
> bridges and interfaces.
>
>
> On Thu, 22 Aug 2013 09:32:42 -0700
> Tony Su <address@hidden> wrote:
>
>> Have you
>> - Tested without VLAN tags?
>
> Yes, works perfectly.
>
>> - Verified IP Forwarding is enabled, I usually see this implemented in
>> /etc/sysctl.conf and not written directly to the /proc files
>
> Yes, forwarding is active.
>
>> - Disabled all the transparent bridge filters, typicallly at
>> /proc/sys/net/bridge/* again, although you can write directly to these
>> files I'd recommend you simply add the commands to your sysctl.conf
>
> Yes, I played with these a bit but found out that there is no effect on my
> problem.
>
>> - Verified any personal FW is configured properly.
>
> There is none.
>
>> Tony
>>
>> On Thu, Aug 22, 2013 at 7:39 AM, Stephan von Krawczynski
>> <address@hidden> wrote:
>> > Hello all,
>> >
>> > I'd like to do something very simple - at least that's what I thought ;-)
>> > I want a guest to have access to a network just as if he was connected to 
>> > the
>> > real card, but set up as bridge on the host and virtio network driver. The
>> > guest should be able to configure and use some or maybe even many 802.1q 
>> > vlans
>> > on this network and the traffic should go out tagged.
>> >
>> > So I setup the hosts bridge and connected an intel network card and a qemu
>> > virtio card. Now the problem: No vlan-tagged traffic from the physical
>> > interface reaches the guest at all, and no vlan-tagged traffic from the 
>> > guest
>> > reaches the physical net over the bridge. One major reason for this is the
>> > vlan offloading by the host interface card (intel). Another seems to be 
>> > that
>> > arp requests are somehow not going through the bridge for the vlans.
>> >
>> > I hope that someone here has used 802.1q vlans inside guests before and can
>> > share some tips how to make this work. Because out-of-the-box it does not. 
>> > All
>> > system are linux of course and with latest kernels (3.10.9 currently).
>> > qemu is 1.5.2.
>> > Thanks for any hints.
>> >
>> > --
>> > Regards,
>> > Stephan
>> >
>> >
>>
>>
>
> --
> Regards,
> Stephan
>
>