[libvirt] Problem with Open vSwitch and dnsmasq

[Laine Stump]

On 03/22/2012 09:10 AM, Daniele Milani wrote:
> Dear all,
> I have the following situation:
> -I replaced the standard bridge driver with the Open VSwitch one;

I'm curious what you mean by this.

libvirt's virtual networks currently only support the standard linux
bridge device. There is no code in libvirt to use openvswitch devices
for libvirt's virtual networks. The openvswitch support in libvirt only
applies to guest devices that use <interface type='bridge'>.

>From your message, it sounds like there is a driver that that replaces
the linux host bridge driver with something that emulates that driver,
but is actually an openvswitch bridge on the backend. I hadn't
previously heard of this.


> -I started a NAT-network on Libvirt (bridge name virbr1);
> -I started a Virtual Machine (VM1) on Libvirt, and I tagged his
> interface (vnet0) with tag=2;
> -if I run "# ovs-vsctl show" I obtain:
>
> Bridge "virbr1"
>         Port "vnet0"
>             tag: 2
>             Interface "vnet0"
>         Port "virbr1-nic"
>             Interface "virb1-nic"
>         Port "virbr1"
>             Interface "virbr1"
>                 type: internal
>
> -the problem is that it is impossible to assign to VM1 an IP, because
> the dnsmasq daemon does not accept the tagged DHCP Discover frame.
>
> Does someone know if there is a way for dnsmasq to accept tagged
> frames through "virbr1", and send a tagged DHCP Offer packet back to VM1?