[CentOS-virt] proper bridging technoque

Thu Nov 21 22:32:45 UTC 2013
aurfalien <aurfalien at gmail.com>

On Nov 21, 2013, at 2:24 PM, Digimer wrote:

> I'm not sure what you are asking.
> You should not see the vnetX devices from the VM (or even the VM's
> definition file). They're created as needed to link the VM's interface
> to the bridge. Think of them as simple network cables.
> Some of the formatting isn't showing well on my mail client (text only),
> so I am having a little trouble parsing some of the data...
> If the VMs are using br6, then you see that it's already at 9000, so you
> should be able to use 9000 from inside the VM as well. Trick is, the
> vnetX devices are connected to the br0 bridge instead, which is set to
> 1500 because eth0 is still 1500. So at this point, the VMs are
> traversing br0, not br6.
> As for 'virbr0', that is libvirtd's default NAT'ed bridge. I don't
> recommend using those. I usually destroy them, personally.
> So to fix your problem, you need to tell the VMs to use br6. If you want
> to use jumbo frames on br0, you need to increase the MTU of eth0.
> Remember that the bridge will use the MTU of the lowest connected device.

So far my current VMs that work, I see there network as;

Host device vnet 0 (Bridge 'br0')

I do not see a;

Host device vnet# (Bridge 'br6')

My ints of interest are set to jumbo so thats not a prob.  I think the prob is that I am missing the vnet bridge device for eth6.

So I'm curious why its not there and how do I create it?

- aurf