In my previous article Deploy a Ubuntu Based Flannel K8S Cluster in Azure with ARM Template and Kubeadm [https://msazure.club/deploy-a-ubuntu-based-flannel-k8s-cluster-in-azure-with-arm-template-and-kubeadm/] , I provided an Azure ARM template to deploy a flannel networking K8S cluster on Azure. But how flannel networking works, in this article we will discuss a little