How to bridge network

[Michal Prívozník]

On 10/2/22 15:21, Richard W.M. Jones wrote:
> On Thu, Sep 29, 2022 at 07:11:33AM +0000, c.buhtz at posteo.jp wrote:
>> Hello,
>>
>> usually I am a user of VirtualBox. There it is very easy to
>> configure a VM that way that it is visible in the current local
>> network (e.g. a home network with one simple rooter). You have to
>> configure "bridge network" in the VM.
>>
>> I tried to do this with "virt-manager", too. But it wants the name
>> of a device and can't find it. I was looking around in the
>> documentation and for a HowTo but couldn't find something. I only
>> can find tutorials about vanially qemu configurations where I have
>> to manipulate the network config files of my own host. That is not
>> an option. VirtualBox can handle that by its own. And I assume that
>> qemu is much more developed that VB and it is possible somehow.
>>
>> I know my description is to broad for a detailed answer. But maybe
>> you can point me into the right direction, give me a link to a howto
>> or ask some important questions that makes me think. ;)
> 
> It's definitely much harder than it needs to be, but the documentation
> is here:
> 
> https://wiki.libvirt.org/page/Networking#Bridged_networking_.28aka_.22shared_physical_device.22.29
> 
> Rich.
> 

Alternatively, you can use <interface type='direct'/> (aka macvtap)
which creates a "shadow" interface on the top of a physical NIC and
shares the network fabric. The only limitation here is that the guest
won't be accessible from the host until your switch is able to send
packets back the same port they came (aka hairpin) - accessible via
network, the graphical/serial consoles are still available. To work
around this you can add another <interface/> but I guess it's easier to
just use graphical console and/or turn on the hairpin.

Michal