Connecting a virtual machine to an OVN-Kubernetes secondary network

Create a NetworkAttachmentDefinition object:

apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  name: l2-network
  namespace: my-namespace
spec:
  config: |-
    {
            "cniVersion": "0.3.1", (1)
            "name": "my-namespace-l2-network", (2)
            "type": "ovn-k8s-cni-overlay", (3)
            "topology":"layer2", (4)
            "mtu": 1300, (5)
            "netAttachDefName": "my-namespace/l2-network" (6)
    }

Apply the manifest:

$ oc apply -f <filename>.yaml

Create a NetworkAttachmentDefinition object:

apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  name: localnet-network
  namespace: default
spec:
  config: |-
    {
            "cniVersion": "0.3.1", (1)
            "name": "localnet-network", (2)
            "type": "ovn-k8s-cni-overlay", (3)
            "topology": "localnet", (4)
            "netAttachDefName": "default/localnet-network" (5)
    }

Apply the manifest:

$ oc apply -f <filename>.yaml

Go to Networking → NetworkAttachmentDefinitions in the web console.

Click Create Network Attachment Definition. The network attachment definition must be in the same namespace as the pod or virtual machine using it.

Enter a unique Name and optional Description.

Select OVN Kubernetes L2 overlay network from the Network Type list.

Click Create.

Navigate to Networking → NetworkAttachmentDefinitions in the web console.

Click Create Network Attachment Definition. The network attachment definition must be in the same namespace as the pod or virtual machine using it.

Enter a unique Name and optional Description.

Select OVN Kubernetes secondary localnet network from the Network Type list.

Enter the name of your pre-configured localnet identifier in the Bridge mapping field.

Optional: You can explicitly set MTU to the specified value. The default value is chosen by the kernel.

Optional: Encapsulate the traffic in a VLAN. The default value is none.

Click Create.

Edit the VirtualMachine manifest to add the OVN-Kubernetes secondary network interface details, as in the following example:

apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: vm-server
spec:
  running: true
  template:
    spec:
      domain:
        devices:
          interfaces:
          - name: secondary (1)
            bridge: {}
        resources:
          requests:
            memory: 1024Mi
      networks:
      - name: secondary  (2)
        multus:
          networkName: <nad_name> (3)
# ...

Apply the VirtualMachine manifest:

$ oc apply -f <filename>.yaml

Optional: If you edited a running virtual machine, you must restart it for the changes to take effect.