Transport endpoint is not connected

Transport endpoint is not connected
from HungryLemon@lemmings.world to linux@lemmy.ml on 30 Apr 13:27
https://lemmings.world/post/25265819

Hi, folks! 👋

I want to create a local ip address for my virtual machine. I use virt-manager + QEMU. So, as I got it - I need to create a bridge for doing this. But… When I’m trying to connect a created bridge to a virtual machine:

Then trying to start a virtual machine, I gets this error:

Ошибка запуска домена: /usr/lib/qemu/qemu-bridge-helper --use-vnet --br=br0 --fd=32: failed to communicate with bridge helper: stderr=failed to create tun device: Operation not permitted
: 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/dist-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=failed to create tun device: Operation not permitted
: Transport endpoint is not connected

For creating bridges I use the standard network manager for Xfce:

I use MX Linux operating system for the host machine.

So, what do I do wrong, and how can I fix this problem? 🤔

#linux

threaded - newest

INeedMana@lemmy.world on 30 Apr 13:53 next collapse

stderr=failed to create tun device: Operation not permitted

you probably don’t have permissions to create such device. BTW, afaik a bridge will make the vm get the traffic on the same IP, creating a separate IP for VM will probably be something else. And might require some iptables setup so your host machine relays the traffic

just_another_person@lemmy.world on 30 Apr 15:38 collapse

Yes, if not doing this as sudo, you need to be part of the proper group to create and alter network interfaces.

HungryLemon@lemmings.world on 30 Apr 19:43 next collapse

What is this group?

just_another_person@lemmy.world on 30 Apr 20:34 collapse

Depends on the distro and how you have your permissions configured.

HungryLemon@lemmings.world on 30 Apr 19:48 collapse

I checked the groups of my user, and my user is already in the netdev group 🤔

Maybe I need to add it to another group?

just_another_person@lemmy.world on 30 Apr 20:33 collapse

The easiest test is to run the creation commands as sudo or root. If it works, then you need a different permissions setup. You didn’t mention any specifics about your distro permissions setup.

HungryLemon@lemmings.world on 30 Apr 21:37 collapse

Thanks so much! 😄 I finally solved my problem 😉

First step that I’ve do - I found this article 👉 …wordpress.com/…/using-qemu-with-a-bridge-network… and doing all from there.

The next step - I’ve add a bridge to an existing network interface:

sudo brctl addif br0 eth0

And the next step - I’ve started up this bridge:

sudo ip link set br0 up

And now everything works fine 👍