[libvirt] when define NAT network, assign what kind of forward dev is better

[Laine Stump]

On 03/06/2013 11:30 PM, yue wrote:
> hi all:
> in my case, my physical machine has one ethernet, i want to use both
> bridge and nat network.
> i create a bridge outbr0(addif eth0),  when creating NAT network,
> there are 3 options for forward-dev
> 1.<forward mode="nat" />
> 2.<forward mode="nat" dev="outbr0"/>
> 3.<forward mode="nat" dev="eth0"/>
>
> i do not know which one is the best?

In general, don't ever use the forward dev. It does nothing to change
the routing of packets, only rejects packets which get routed out any
interface other than the specified dev.

In your case if you *really* wanted to specify a forward device, you
would want outbr0.