$ cat nad.yaml
apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  name: layer2ipv4network
spec:
  config: |2
    {
            "cniVersion": "0.3.1",
            "name": "layer2ipv4network",
            "type": "ovn-k8s-cni-overlay",
            "topology":"layer2",
            "subnets": "192.168.100.0/24",
            "mtu": 1300,
            "netAttachDefName": "test/layer2ipv4network"
    }
kind: Pod
apiVersion: v1
metadata:
  name: multihoming-ipv4-pod1
  labels:
    name: multihoming-ipv4-pod1
  annotations:
    k8s.v1.cni.cncf.io/networks: layer2ipv4network
spec:
  securityContext:
    runAsNonRoot: true
    seccompProfile:
      type: RuntimeDefault
  containers:
  - name: multihoming-ipv4-pod1
    image: quay.io/openshifttest/hello-sdn@sha256:c89445416459e7adea9a5a416b3365ed3d74f2491beb904d61dc8d1eb89a72a4
    securityContext:
      allowPrivilegeEscalation: false
      capabilities:
        drop: ["ALL"]
## Pass in 4.16 
$ oc get clusterversion
NAME      VERSION                              AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.16.0-0.nightly-2025-01-31-045344   True        False         4h12m   Cluster version is 4.16.0-0.nightly-2025-01-31-045344
$ oc create -f nad.yaml
networkattachmentdefinition.k8s.cni.cncf.io/layer2ipv4network created
$ oc create -f pod.yaml 
pod/multihoming-ipv4-pod1 created
$ oc get pod
NAME                    READY   STATUS    RESTARTS   AGE
multihoming-ipv4-pod1   1/1     Running   0          5s

# Fail in 4.19
$ oc get clusterversion
NAME      VERSION                              AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.19.0-0.nightly-2025-01-30-091858   True        False         3h17m   Cluster version is 4.19.0-0.nightly-2025-01-30-091858
$ oc create -f nad.yaml
networkattachmentdefinition.k8s.cni.cncf.io/layer2ipv4network created
$ oc create -f pod.yaml 
pod/multihoming-ipv4-pod1 created
$ oc get pod
NAME                    READY   STATUS              RESTARTS   AGE
multihoming-ipv4-pod1   0/1     ContainerCreating   0          2m36s
$ oc describe pod multihoming-ipv4-pod1
Name:             multihoming-ipv4-pod1
Namespace:        test
Priority:         0
Service Account:  default
Node:             ip-10-0-59-120.us-east-2.compute.internal/10.0.59.120
Start Time:       Fri, 31 Jan 2025 15:05:19 -0500
Labels:           name=multihoming-ipv4-pod1
Annotations:      k8s.ovn.org/pod-networks:
                    {"default":{"ip_addresses":["10.131.0.51/23"],"mac_address":"0a:58:0a:83:00:33","gateway_ips":["10.131.0.1"],"routes":[{"dest":"10.128.0.0...
                  k8s.v1.cni.cncf.io/networks: layer2ipv4network
                  openshift.io/scc: restricted-v2
                  seccomp.security.alpha.kubernetes.io/pod: runtime/default
Status:           Pending
SeccompProfile:   RuntimeDefault
IP:               
IPs:              <none>
Containers:
  multihoming-ipv4-pod1:
    Container ID:   
    Image:          quay.io/openshifttest/hello-sdn@sha256:c89445416459e7adea9a5a416b3365ed3d74f2491beb904d61dc8d1eb89a72a4
    Image ID:       
    Port:           <none>
    Host Port:      <none>
    State:          Waiting
      Reason:       ContainerCreating
    Ready:          False
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-lvcmb (ro)
Conditions:
  Type                        Status
  PodReadyToStartContainers   False 
  Initialized                 True 
  Ready                       False 
  ContainersReady             False 
  PodScheduled                True 
Volumes:
  kube-api-access-lvcmb:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
    ConfigMapName:           openshift-service-ca.crt
    ConfigMapOptional:       <nil>
QoS Class:                   BestEffort
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason                  Age   From               Message
  ----     ------                  ----  ----               -------
  Normal   Scheduled               3m2s  default-scheduler  Successfully assigned test/multihoming-ipv4-pod1 to ip-10-0-59-120.us-east-2.compute.internal
  Warning  FailedCreatePodSandBox  63s   kubelet            Failed to create pod sandbox: rpc error: code = Unknown desc = failed to create pod network sandbox k8s_multihoming-ipv4-pod1_test_0a9b931f-d20f-497f-831f-7b1302cc65d8_0(36431cbb1b6b487e1ecb3758922db87328f9e58a0ea74fa2453834b5f1afb621): error adding pod test_multihoming-ipv4-pod1 to CNI network "multus-cni-network": plugin type="multus-shim" name="multus-cni-network" failed (add): CmdAdd (shim): CNI request failed with status 400: 'ContainerID:"36431cbb1b6b487e1ecb3758922db87328f9e58a0ea74fa2453834b5f1afb621" Netns:"/var/run/netns/3bdfa373-0940-45b1-b3e5-8d4213ff96ee" IfName:"eth0" Args:"IgnoreUnknown=1;K8S_POD_NAMESPACE=test;K8S_POD_NAME=multihoming-ipv4-pod1;K8S_POD_INFRA_CONTAINER_ID=36431cbb1b6b487e1ecb3758922db87328f9e58a0ea74fa2453834b5f1afb621;K8S_POD_UID=0a9b931f-d20f-497f-831f-7b1302cc65d8" Path:"" ERRORED: error configuring pod [test/multihoming-ipv4-pod1] networking: [test/multihoming-ipv4-pod1/0a9b931f-d20f-497f-831f-7b1302cc65d8:layer2ipv4network]: error adding container to network "layer2ipv4network": CNI request failed with status 400: '[test/multihoming-ipv4-pod1 36431cbb1b6b487e1ecb3758922db87328f9e58a0ea74fa2453834b5f1afb621 network layer2ipv4network NAD test/layer2ipv4network] [test/multihoming-ipv4-pod1 36431cbb1b6b487e1ecb3758922db87328f9e58a0ea74fa2453834b5f1afb621 network layer2ipv4network NAD test/layer2ipv4network] failed to get pod annotation: timed out waiting for annotations: context deadline exceeded
'
': StdinData: {"binDir":"/var/lib/cni/bin","clusterNetwork":"/host/run/multus/cni/net.d/10-ovn-kubernetes.conf","cniVersion":"0.3.1","daemonSocketDir":"/run/multus/socket","globalNamespaces":"default,openshift-multus,openshift-sriov-network-operator,openshift-cnv","logLevel":"verbose","logToStderr":true,"name":"multus-cni-network","namespaceIsolation":true,"type":"multus-shim"}
  Normal  AddedInterface  62s (x2 over 3m3s)  multus  Add eth0 [10.131.0.51/23] from ovn-kubernetes