Hello! I think you might forget to "up" the tap interface.
In short you just need to add your host physical interface and virtual tap interface (connected to the guest) to the same bridge: ifconfig tap0 create up //chmod a+rw /dev/tap0 to run QEMU as non-root ifconfig bridge0 create brconfig bridge0 add wm0 add tap0 up then start QEMU with the following options: -netdev tap,id=net0,ifname=tap0,script=no,downscript=no -device virtio-net-pci,netdev=net0 Now your guest can communicate outside the virtual machine. On Thu, Jul 3, 2025 at 3:05 AM Michael van Elst <mlel...@serpens.de> wrote: > > On Wed, Jul 02, 2025 at 03:17:42PM -0600, Brook Milligan wrote: > > > > > The key is that the host needs an address on the bridge in the guest?s > > subnet so it can route packets. > > When you add the host ethernet interface to the bridge, you do not route > packets and you do not have a "guest subnet". It's all one, just like > connecting the guest to the same switch the host is connected to. > > > I?m not sure what ?neither? refers to. In my experience testing this, some > > interface attached to the bridge (either tap or vether) needs an IP address > > for routing. > > Connecting to the bridge connects the interfaces on layer 2, routing > is not part of this and not required. Also, for connectivity to the > outside, a routed guest network also needs proper routes on the host > network. You can do that, but it adds lots of complexity. > > > Greetings, > -- > Michael van Elst > Internet: mlel...@serpens.de > "A potential Snark may lurk in every tree."
