BGP routes not advertised - in the speaker pods logs we can see messages about "invalid allowed prefixes"
    

- Started to see this in OpenShift 4.20 nightly 2025-06-28 11:54 and newer.
- MetalLB pre-ga operator: 4.19.0
    

100%
    

`
    

BGP routes not being advertised
    

BGP routes are advertised
    

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc get clusterversion
NAME      VERSION                              AVAILABLE   PROGRESSING   SINCE   STATUS                                                                      
version   4.20.0-0.nightly-2025-07-01-051543   True        False         10h     Cluster version is 4.20.0-0.nightly-2025-07-01-051543 

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-system get csv | grep metal                                                                           
metallb-operator.v4.19.0                   MetalLB Operator                           4.19.0                Succeeded                                        
[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-system get pods
NAME                                                   READY   STATUS    RESTARTS   AGE                                                                      
controller-7b688cf4db-xb7dx                            2/2     Running   0          8h                                                                       
metallb-operator-controller-manager-6b98b445b8-qfw7f   1/1     Running   0          9h                                                                       
metallb-operator-webhook-server-6d84c4bfd8-djxbm       1/1     Running   0          9h                                                                       
speaker-k8g24                                          2/2     Running   0          8h                                                                       
speaker-ks64v                                          2/2     Running   0          8h                                                                       
speaker-q7qmq                                          2/2     Running   0          8h                                                                       
speaker-tx95z                                          2/2     Running   0          8h

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-system logs speaker-k8g24 | grep error | tail -1                                                      
Defaulted container "speaker" out of: speaker, kube-rbac-proxy
{"level":"error","ts":"2025-07-02T20:02:38Z","msg":"Reconciler error","controller":"frrconfiguration","controllerGroup":"frrk8s.metallb.io","controllerKind":"FRRConfiguration","FRRConfiguration":{"name":"reload","namespace":"metallbreload"},"namespace":"metallbreload","name":"reload","reconcileID":"89ee1bec-00b7-496c-8dbd-be45dd238fa6","error":"admission webhook \"frrconfigurationsvalidationwebhook.metallb.io\" denied the request: invalid allowed prefixes [10.100.1.50/32 fdb4:da34:100:1::5/128] for neighbor 65000@192.168.15.2, err: prefix fdb4:da34:100:1::5/128 is not compatible with the ipfamily ipv4\nresource is invalid for node worker-3","stacktrace":"sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller[...]).reconcileHandler\n\t/metallb/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:341\nsigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller[...]).processNextWorkItem\n\t/metallb/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:288\nsigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller[...]).Start.func2.2\n\t/metallb/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:249"}

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-app-vlan404 get pods
NAME                               READY   STATUS    RESTARTS   AGE
httpbin-vlan404-5dc856c46d-j97sp   1/1     Running   0          8h
httpbin-vlan404-5dc856c46d-kk4v9   1/1     Running   0          8h

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-app-vlan404 get service
NAME              TYPE           CLUSTER-IP     EXTERNAL-IP                      PORT(S)          AGE
metallb-vlan404   LoadBalancer   172.30.19.14   10.100.1.50,fdb4:da34:100:1::5   8080:32267/TCP   8h

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-app-vlan404 get service metallb-vlan404 -o json | jq .spec
{
  "allocateLoadBalancerNodePorts": true,
  "clusterIP": "172.30.19.14",
  "clusterIPs": [
    "172.30.19.14",
    "fd03::437"
  ],
  "externalTrafficPolicy": "Cluster",
  "internalTrafficPolicy": "Cluster",
  "ipFamilies": [
    "IPv4",
    "IPv6"
  ],
  "ipFamilyPolicy": "PreferDualStack",
  "ports": [
    {
      "nodePort": 32267,
      "port": 8080,
      "protocol": "TCP",
      "targetPort": 8080
    }
  ],
  "selector": {
    "app": "vlan404"
  },
  "sessionAffinity": "None",
  "type": "LoadBalancer"
}
[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-system get IPAddressPool
NAME      AUTO ASSIGN   AVOID BUGGY IPS   ADDRESSES
vlan404   true          false             ["10.100.1.50-10.100.1.70","fdb4:da34:100:1::5-fdb4:da34:100:1::10"]

[kni@provisioner.cluster1.dfwt5g.lab ~]$ oc -n metallb-system get BGPAdvertisement vlan404 -o yaml                                                           
apiVersion: metallb.io/v1beta1
kind: BGPAdvertisement
metadata:
  creationTimestamp: "2025-07-02T11:13:45Z"
  generation: 1
  name: vlan404
  namespace: metallb-system
  resourceVersion: "153443"
  uid: ff760a3f-269c-4625-aeea-88f9aa68fe2b
spec:
  aggregationLength: 32
  aggregationLengthV6: 128
  ipAddressPools:
  - vlan404
  peers:
  - dfw01edge-sp01-cluster1-vlan404-ipv4
  - dfw01edge-sp02-cluster1-vlan404-ipv4
  - dfw01edge-sp01-cluster1-vlan404-ipv6
  - dfw01edge-sp02-cluster1-vlan404-ipv6