Re: libvirt guest bridge configuration

[Dan Ritter <dsr@randomstring.org>]

Lucio Crusca wrote: 
> I'm trying to bridge a network interface between host and guest (both Debian
> Buster+Bullseye+Sid) so that NAT is not needed.
> 
> In the host /etc/network/interfaces I've declared a bridge like this:
> 
> auto eno1
> iface eno1 inet static
>   address 2.4.6.8
>   netmask 255.255.255.224
>   gateway 2.4.6.1
>   up route add -net 2.4.6.0 netmask 255.255.255.224 gw 2.4.6.1 dev eno1
> 
> 
> auto virbr-dummy
> iface virbr-dummy inet manual
>     pre-up /sbin/ip link add virbr-dummy type dummy
>     up /sbin/ip link set virbr-dummy address 52:54:00:f0:37:ba


> 
> 
> auto virbr10
> iface virbr10 inet static
>     bridge_ports virbr-dummy
>     bridge_stp on
>     bridge_fd 2
>     address 2.4.6.73
>     netmask 255.255.255.224
>     gateway 2.4.6.65
>     broadcast 2.4.6.95
>     up route add -net 2.4.6.64 netmask 255.255.255.224 gw 2.4.6.65 dev eno1

auto eno1
iface eno1 manual

auto virbr10
iface virb10 inet static
  bridge_ports eno1
  bridge_stp off
  address 2.4.6.8
  netmask 255.255.255.224
  gateway 2.4.6.1

the bridge eats the eno1 interface.

The virtual machine setup should add a new bridge_port to the
bridge when it comes up, and remove it when it comes down.

Now the virtual machine interfaces can be on the same network
as the bridge is.

No need for a virbr-dummy.

-dsr-