Linux

You need to add a physical interface to the bridge. Whatever the one in the "default" connection is probably.

It looks like you haven't actually created any bridges, just asked virt-manager to use one. If you type: ip a In a terminal it will list your network adapters. If br0 isn't listed it doesn't exist.

I think nmcli is the easier way to go but this article from redhat has what your looking for in 6.4

Okay. A little context is needed.

Qemu is just the emulator used. For the most part, it cannot handle networking.

Libvirt, is a system daemon, that handles running qemu and whatnot, and also configuring networking. Virt-manager, interacts with this libvirt daemon.

Now, by default, libvirt creates a bridge for all virtual machines to use, to create a simple one-to-many NAT.

The above is looking at the bridge on my laptop*. However, each virtual network has to be started.

Then, when you create a virtual machine, it should automatically select the bridge interface, and no further configuration should be required...

However, that's just NAT. But configuring the other virtual networking types should also be doable from the virt-manager as well, and I find it kinda weird that you are going to NetworkManager for this. The default is NAT, but

By "multiple local ips", do you mean something like how virtual machines share a physical device (possibly with the host?), and get their own ip address on the same network as the host?

Macvtap is probably the easier way to do that, just select macvtap and the physical device you want to attatch your virtual machine to, however, there are caveats with host-guest network communication.

Bridged is more complex, especially when you only have one physical ethernet port. Converting an ethernet interface to a bridge usually also prevents it from being used as a normal ethernet port.

The easier, more reliable, tested method requires two ethernet interfaces, both plugged in and connect.

Create a bridge in Networkmanager, and select the non-host interface, as a bridge:

There is a less reliable way if you only have one ethernet interface: if you have only one port, you can convert it to a usable network interface. Although you can do this by hand in NetworkManage (or whatever network management service you are using), there is a much easier way:

1. Install Cockpit
2. Go to the networking section
3. Create a bridge, and add your main ethernet interface as a port.

After that, cockpit will automatically configure bridge to be a usable internet interface as well, and then you can select that bridge as your bridge in virt-manager....

Except I had some issues with nested bridging on kernels older than 6.0, so obviously setup adds extra complexity.

Anyway, I highly recommend you access cockpit remotely, rather than over RDP, if you are going to do this, so that cockpit can properly test the network connection (it automatically reverts changes within a time period if they break connectivity).

I also recommend reading: https://jamielinux.com/docs/libvirt-networking-handbook/ for an understanding of libvirt networking, and which

*okay, maybe inline images are kinda nice. I thought they were annoying at first but they obviously have utility.