How can I use create a bridge network for different VLANs so my host + guest can connect to different VLANs?

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My box has Debian 12, KDE, and is using Network Manager.

I am using virt-manager and want to create VMs on different VLANs on my network.

My box is connected to a port on my switch that allows VLAN 10 and 20.

I figured out how to create a bridge network from the Network Manager GUI (plasma-nm) (screenshots below)

  1. disalbe auto connect for my default/main/physical ethernet (LAN => eno1)
  2. create a new bridged network, add ethernet that is restricted to eno1, disable STP

What I can’t figure out is bridge + VLANs. I want:

  1. my host to join VLAN 10
  2. some VMs on 10
  3. some VMs on 20

for this to work, I assume (???) I need 2 bridged connections:

  1. one for VLAN 10 that my host and VMs will use
  2. one for VLAN 20 that VMs will use

Is this right? How do I configure this from the GUI?

My default wired connection set to not auto connect

enter image description here

New bridged connection restricted to eno1

enter image description here

2

A GNOME forum is a somewhat odd place to ask a question about KDE Settings :wink:

Someone may know of course, but it’s not the core expertise of most people here.

3

Network Manager is a Gnome utility. It just happens to be used everywhere now. The Network Manager website listed this forum as a support place. I figured it was worth a shot.

4

It is a freedesktop project.

The Network Manager website listed this forum as a support place

Interesting. I mean, this is definitively the right place for questions about NetworkManager integration in GNOME. I’m less sure about NetworkManager questions in general, and Networkmanager integration in non-GNOME desktops seems … quite a shot.

I figured it was worth a shot.

Sure. There’s nothing wrong with asking, and I hope my reply didn’t come across like that. It just seems a long-shot, that’s all I’m saying.

1 Like
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It didn’t. I spent days Googling with no luck. When you’re desprate, you’ll try anything. Heh.

6

NetworkManager (core) is a GNOME and a freedesktop project. E.g. the source tarballs are on download.gnome.org, NetworkManager used the GNOME mailing list (before it shut down). It’s surely appropriate to ask NetwrokManager on discourse.gnome.org. Note that Community suggests to ask for help on the mailing list or on IRC instead.

NetworkManager is also supposed to work similar, on KDE and GNOME. The GUIs may look different, but the concepts and underlying daemon are the same.

Anyway. You can create a VLAN device that gets attached to the bridge, like nmcli connection add type vlan slave-type bridge master br0 .... In that case, I guess you would need two separate bridge profiles/devices, that join the different VLANs.

Alternatively, the bridge has properties like bridge.vlan-filtering and the ports have bridge-bridge.vlans property. I suspect you could also have only one bridge interface with multiple vlans. I am not sure. See man nm-settings-nmcli.

7

So far I have done everything through the GUI with the assumption the GUI should let me do what I need/want.

So far, it seems to be a bug because everyone says what I am doing should work, but it doesn’t.

I opened a bug at KVM VM is not getting IPv4 but is getting IPv6 when using DHCP with VLAN bridge on Linux host using network manager (#1351) · Issues · NetworkManager / NetworkManager · GitLab.

I will try the mailing list. Thank you!

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