<p>I install kubernetes v1.11.5 from kubeadm with cni plugin flannel and everything is ok. But I after try to switch to calico I found that the cross machine pod communication is broken. So I switch back to flannel. But got error message when creating pod:</p>

<p><a href="https://i.stack.imgur.com/V8dN5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/V8dN5.png" alt="enter image description here"></a></p>

<p>It seems that I need to reset cni network? But I don't know how to solve this problem. </p>

<p>My flannel and calico installation is follow <a href="https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/" rel="nofollow noreferrer">kubeadm instruction</a> with zero config update.</p>

<p>I use following steps to remove old calico configs from kubernetes without <code>kubeadm reset</code>:</p>

<ol>
<li>clear ip route: <code>ip route flush proto bird</code></li>
<li>remove all calico links in all nodes <code>ip link list | grep cali | awk '{print $2}' | cut -c 1-15 | xargs -I {} ip link delete {}</code></li>
<li>remove ipip module <code>modprobe -r ipip</code></li>
<li>remove calico configs <code>rm /etc/cni/net.d/10-calico.conflist &amp;&amp; rm /etc/cni/net.d/calico-kubeconfig</code></li>
<li>restart kubelet <code>service kubelet restart</code></li>
</ol>

<p>After those steps all the running pods won't be connect, then I have to delete all the pods, then all the pods works. This has litter influence if you are using <code>replicaset</code>.</p>
