Enable strictARP in kube-proxy

If you’re using kube-proxy in IPVS mode, since Kubernetes v1.14.2 you have to enable strict ARP mode.

NOTE - this is not needed if you’re using kube-router as service-proxy because it is enabling strict ARP by default.

Achieve this by patching your kube-proxy config in current cluster:

# see what changes would be made, returns nonzero returncode if different
kubectl get configmap kube-proxy -n kube-system -o yaml | \
sed -e "s/strictARP: false/strictARP: true/" | \
kubectl diff -f - -n kube-system

# actually apply the changes, returns nonzero returncode on errors only
kubectl get configmap kube-proxy -n kube-system -o yaml | \
sed -e "s/strictARP: false/strictARP: true/" | \
kubectl apply -f - -n kube-system

• If using kubespray for your cluster deployment, make sure to add the following variable:

kube_proxy_strict_arp: true