Why is the localnet user defined network not working?

Virtual Private Cloud 4.20 and later Bare metal worker nodes only RHCOS only

You configure a localnet user defined network (UDN) for OpenShift Virtualization, but the network does not work as expected.

A localnet UDN depends on the NMState Operator, an OVS bridge on eth1, a bridge mapping, and a matching VLAN configuration in the ClusterUserDefinedNetwork (CUDN). If any part of this setup is missing or inconsistent, the network does not work correctly.

To resolve the issue,

verify the NMState installation, the OVS bridge, the bridge mapping, and the VLAN configuration.

1. Verify that the NMState Operator pods are running.

   oc get pods -n openshift-nmstate
   

2. Check the OVS bridge configuration.

   oc get nodenetworkconfigurationpolicy
   oc describe nodenetworkconfigurationpolicy br-eth1
   

3. Verify the bridge mapping configuration.

   oc get nodenetworkconfigurationpolicy
   oc describe nodenetworkconfigurationpolicy vpc-vlans
   

4. Verify that the VLAN ID in the CUDN matches the VLAN that you plan to use.

   oc get clusteruserdefinednetwork <cudn_name> -o yaml | grep vlan
   ibmcloud ks vni ls --cluster-id <cluster_id>
   

5. Review Managing virtual network interfaces for OpenShift Virtualization to confirm that the OVS bridge, bridge mapping, and CUDN definitions match the documented configuration.