1. Testing the Full Bandwidth Start the iperf3 server on the target host 1 2 3 4 5 iperf3 -s ----------------------------------------------------------- Server listening on 5201 ----------------------------------------------------------- Test from the client host 1 iperf3 -c x.x.x.x -p 5201 -t 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Connecting to host x.

This article is translated from https://learnk8s.io/kubernetes-network-packets, not word for word, with some of my own understanding worked in. By reading this article, you can learn how packets are forwarded inside and outside Kubernetes, starting from the original web request all the way to the container hosting the application. Kubernetes Network Requirements Before diving into the details of how packets flow through a Kubernetes cluster, let’s first clarify Kubernetes’ requirements for networking.

1. CNI Problems Error log 1 2 journalctl -u kubelet ...Unable to update cni config: No networks found in /etc/cni/net.d Because no CNI is installed, you need to remove --network-plugin=cni from the parameters in /var/lib/kubelet/kubeadm-flags.env. 1 2 cat /var/lib/kubelet/kubeadm-flags.env KUBELET_KUBEADM_ARGS="--cgroup-driver=systemd --pod-infra-container-image=k8s.gcr.io/pause:3.1" 2. Node NotReady There can be many reasons for a node being NotReady.

1. Docker’s Network Model 1.1 bridge Mode bridge mode is used by default, and you can also specify it with --net=bridge. In bridge mode, containers connect to the same virtual bridge, docker0. docker0 usually occupies the 172.17.0.1/16 subnet. Containers on the same bridge can communicate directly over IP. 1.2 host Mode Use --net=host to specify host mode.