Virt Manager: Bridge Network Setup

I’ve worked through a few issues and the thread here on how to properly setup VirtManager was very helpful: LINK

I initially had an issue with libvirtd it was looking for a user swtpm and I had to install the swtpm package as well. Then I could follow basically any tutorial on how to setup a bridge interface using nmcli.

I added a br0 device to virsh,

 Name      State      Autostart   Persistent
 br0       active     yes         yes
 default   inactive   no          yes

So I feel like I’m pretty close. My current network setup is running through the bridge so it all works. FINALLY.

The one last thing I’m trying to get working is having my VM’s in VirtManager run on my br0 network. I update the virtual NIC under VM >> Hardware Information, and I set:

NetworkSoruce: Bridge Device
Device Name: br0
Device Model: virtio

And I get this error out. Any ideas?

Error starting domain: /usr/lib/qemu/qemu-bridge-helper --use-vnet --br=br0 --fd=32: failed to communicate with bridge helper: stderr=access denied by acl file
: Transport endpoint is not connected

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 72, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 108, in tmpcb
    callback(*args, **kwargs)
  File "/usr/share/virt-manager/virtManager/object/libvirtobject.py", line 57, in newfn
    ret = fn(self, *args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/share/virt-manager/virtManager/object/domain.py", line 1402, in startup
    self._backend.create()
  File "/usr/lib/python3.11/site-packages/libvirt.py", line 1373, in create
    raise libvirtError('virDomainCreate() failed')
libvirt.libvirtError: /usr/lib/qemu/qemu-bridge-helper --use-vnet --br=br0 --fd=32: failed to communicate with bridge helper: stderr=access denied by acl file
: Transport endpoint is not connected
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Shoot I answered my own question. This site has a great write up on it. It’s a security feature around who can start devices connecting to the bridge.

https://blog.christophersmart.com/2016/08/31/configuring-qemu-bridge-helper-after-access-denied-by-acl-file-error/

I followed the steps to create a user specific allow, and it kicks off fine now. :clap:

1 Like