Incus networking for network engineers

Is there any way to build out Incus networking in the same way a network engineer builds out switches, switchports, VLANs, trunks - without automatic setup of DNSMASQ and NAT?

I’m setting up Incus on Debian 12 in a VMware vCenter virtual machine connected to a distributed port group (VLAN). I want to interconnect Incus containers through the distributed switch into an NSX underlay/overlay infrastructure and do not want to wrestle with NAT and DNSMASQ or any other service that Incus configures automatically.

Is there any way to build up Incus networking like one builds a Cisco infrastructure?

You can have an unmanaged bridge (OS created) with vlan_filtering enabled on it, at which point you can attach Incus instances do whatever VLANs you want.

Looks like:

incus config device add MY-INSTANCE eth0 nic nictype=bridged name=eth0 parent=br0 vlan=1000 vlan.tagged=2000,2001

Which will then get you a native VLAN of 1000 and tagged VLANs for ID 2000 and 2001 in the instance.

In this case, you do need to configure br0 on your system through your OS’ network management tool (systemd-network, NetworkManager, netplan, …) and need to ensure that the vlan_filtering flag is properly set and that the uplink device for your bridge (usually enpXs0 device) has all the correct tags set on it too.

On Ubuntu with netplan it looks something like:

  bridges:
    # Main bridge
    br0:
      interfaces:
        - enp5s0
cat /etc/systemd/network/10-netplan-enp5s0.network.d/vlan.conf
[BridgeVLAN]
VLAN=1000
[BridgeVLAN]
VLAN=2000
[BridgeVLAN]
VLAN=2001
cat /etc/systemd/network/10-netplan-br0.netdev.d/vlan.conf 
[NetDev]
Name=br0
Kind=bridge

[Bridge]
MulticastSnooping=false
VLANFiltering=true
2 Likes

Awesome, thank you Stéphane. I’ll give that a go.

Any plans to add a capability into the Incus CLI that can setup a managed bridge interconnect that trunks VLANs out through a host NIC? Such that Incus can create and control a switch that can interconnect Incus Containers to something similar to a Port Group (VLAN) on a VMware Distributed Switch, with the ability to trunk and aggregate uplinks through the host NICs?

VMware ESXi can setup multiple 10G NICs for a VM running an Incus host and such an Incus bridge could punt the VLAN frames into an Overlay network. To do all of this within the Incus CLI would be next level and would mean no messing with Linux networking (Cisco’s IOS CLI is, for the most part, very logical and intuitive - especially the contextual help. I’ve not come across any CLI help system that can match Cisco’s).

Continuing this thought, could Incus interface directly with OVS APIs to extend this management into an OVN infrastructure, at least as far as an OVS? And visa versa from the OVN side, where OVN network engineers could setup Incus networking from an OVS CLI?

One of the things very obvious about Linux networking (at least to me as a network centric admin) is that the network configuration is approached from the point of view of the host/access layer - looking from the host in towards the network. Reinforcement of that perspective seems to come from the fact that a host NIC and its attached bridge interface are not switchports and cannot be configured like a true switchport.

Maybe the answers will become clearer as I work with Incus and NSX and with OVN infrastructure. Cheers.