Multiple running workloads are using the same MAC address.
MAC collisions cause network issues: packet loss, ARP table conflicts, and traffic being delivered to the wrong targets.
Set the KMP_NAMESPACE environment variable:
$ export KMP_NAMESPACE="$(kubectl get pod -A --no-headers -l \
control-plane=mac-controller-manager | awk '{print $1}')"
Query the kmp_mac_collisions metric to see which MACs are colliding
(value > 1 means collision):
$ kubectl exec -n $KMP_NAMESPACE deployment/kubemacpool-mac-controller-manager \
-c manager -- curl -s http://localhost:8080/metrics | grep kmp_mac_collisions
For each colliding MAC, find the VMIs involved:
$ kubectl get vmi -A -o jsonpath='{range .items[*]}{.metadata.namespace}{"\t"}{.metadata.name}{"\t"}{.status.interfaces[*].mac}{"\n"}{end}' | grep -i "<MAC_ADDRESS>"
Remove the collision by deleting or reconfiguring one of the colliding workloads to use a different MAC address.
If you cannot resolve the issue, see the following resources: