[Users] Guest to guest multicast

Moti Asayag masayag at redhat.com
Thu Oct 17 09:08:10 EDT 2013

----- Original Message -----
> From: "Frank Wall" <fw at moov.de>
> To: "Moti Asayag" <masayag at redhat.com>
> Cc: users at ovirt.org
> Sent: Thursday, October 17, 2013 2:12:35 PM
> Subject: Re: [Users] Guest to guest multicast
> Hi Moti,
> On 17.10.2013 08:04, Moti Asayag wrote:
> > I used iperf for testing multicast between the vms. See
> > http://iperf.fr/#multicast
> > for the exact commands.
> thanks, I did a quick test with iperf with a good result (445 out of 446
> datagrams could be received). But still pfSense/FreeBSD CARP/uCARP does
> not work, it seems to be filtered on the oVirt/KVM Host. Have you ever
> heard of this? Any idea?

On ovirt 3.2 we introduced the network-filters feature [1] which prevents guests
from spoofing other mac-addresses than these which assigned by the engine.
The feature is enable by default since introduced (for 3.2 and above)

There is a possibility that the implementation of the VRRP modifies the mac address
to the expected addresses  which be ended in libvirt's filtering 
(using the ebtables) the frames.

Could you try disabling the filter, restart the vms and re-run the test ?
1. On the ovirt-engine run: engine-config -s EnableMACAntiSpoofingFilterRules=false --cver=3.3
   (if you're using ovirt-engine 3.2, make sure to specify it in the --cver= option).
2. Restart the ovirt-engine service
3. Restart the vms 
4. Re-run the test

An alternative might be to use the custom mac address for the vms which serves
as routers to start with 00-00-5E-00-01-XX (as long as the mac address will not 
be replaced by the protocol)

[1] http://www.ovirt.org/Features/Design/Network/NetworkFiltering

> Thanks
> - Frank

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