title: Pods failed to start after switch cni plugin from flannel to calico and then flannel
body: <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>