kubernetes1.4装完后，pod:kube-dns启动失败

照着http://blog.csdn.net/liukuan73/article/details/52821646一步步下来：
[root@master images]# kubectl get nodes
NAME             STATUS    AGE
master.ian.com   Ready     2h
node1.ian.com    Ready     2h
node2.ian.com    Ready     2h[root@master images]# kubectl get pods --all-namespaces
NAMESPACE     NAME                                     READY     STATUS              RESTARTS   AGE
kube-system   etcd-master.ian.com                      1/1       Running             0          2h
kube-system   kube-apiserver-master.ian.com            1/1       Running             0          2h
kube-system   kube-controller-manager-master.ian.com   1/1       Running             0          2h
kube-system   kube-discovery-982812725-txq7n           1/1       Running             0          2h
kube-system   kube-dns-2247936740-c5fy2                0/3       ContainerCreating   0          2h
kube-system   kube-proxy-amd64-50t6o                   1/1       Running             0          2h
kube-system   kube-proxy-amd64-kruyg                   1/1       Running             0          2h
kube-system   kube-proxy-amd64-o7dk5                   1/1       Running             0          2h
kube-system   kube-scheduler-master.ian.com            1/1       Running             0          2h[root@master images]# kubectl describe -n kube-system pod kube-dns-2247936740-c5fy2
Events:
  FirstSeen LastSeen Count From SubobjectPath Type Reason Message
  --------- -------- ----- ---- ------------- -------- ------ -------
  2h 0s 7639 {kubelet master.ian.com} Warning FailedSync Error syncing pod, skipping: failed to "SetupNetwork" for "kube-dns-2247936740-c5fy2_kube-system" with SetupNetworkError: "Failed to setup network for pod \"kube-dns-2247936740-c5fy2_kube-system(9aecaa07-a132-11e6-a988-000c291f315c)\" using network plugins \"cni\": cni config unintialized; Skipping pod"