[Bridge] What are actually ethernet devices (and what does a bridge do?).

[Jeff Mitchell]

On 06/30/2010 04:26 PM, Stef Bon wrote:
> 2010/6/30 richardvoigt at gmail.com<richardvoigt at gmail.com>:
>> The host processor which does the bridging, can also act as a node
>> sending and receiving traffic to the bridged network.  What you see as
>> the "IP address of the bridge" is actually the configuration of the
>> interface representing this connection to the host processor.
>>
>> Packets generated on the bridge host use this IP address as the source
>> address, packets sent to this IP address are processed locally on the
>> bridge host and not forwarded.
>
> Ok, but then you're talking about a router for example, but I see a
> lot of setups for machines hosting
> other virtual machines, where the bridge gets also an ip address,
> which does not make sense to me.
>
> The function of a bridge is to share the physical device with more
> ethernet devices (virtual because they are not connected to a real
> device), and that's it.
>
> Being a bridge between devices and an interface self at the same time
> is confusing.
>
> About creating virtual devices, does anyone know how to create them?
> I've found veth, looks very promising,
> but they seem to come in pairs.

Look at the documentation for your chosen virtual machine solution -- it 
should tell you how (or have built-in capabilities) to create the 
necessary networking devices.

--Jeff