解决Kubernetes1.15.1 部署Flannel网络后pod及容器无法跨主机互通问题

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记一次部署Flannel网络后网络不通问题, 查询网上资料无果

自己记录一下解决过程

现象

[root@k8s-master01 ~]# kubectl get pod -n kube-system
NAME                                    READY   STATUS    RESTARTS   AGE
coredns-5c98db65d4-54j5c                1/1     Running   0          5h44m
coredns-5c98db65d4-jmvbf                1/1     Running   0          5h45m
etcd-k8s-master01                       1/1     Running   2          10d
kube-apiserver-k8s-master01             1/1     Running   2          10d
kube-controller-manager-k8s-master01    1/1     Running   3          10d
kube-flannel-ds-amd64-6h79p             1/1     Running   2          9d
kube-flannel-ds-amd64-bnvtd             1/1     Running   3          10d
kube-flannel-ds-amd64-bsq4j             1/1     Running   2          9d
kube-proxy-5fn9m                        1/1     Running   1          9d
kube-proxy-6hjvp                        1/1     Running   2          9d
kube-proxy-t47n9                        1/1     Running   2          10d
kube-scheduler-k8s-master01             1/1     Running   4          10d
kubernetes-dashboard-7d75c474bb-hg7zt   1/1     Running   0          71m

[root@k8s-master01 ~]# kubectl get node
NAME           STATUS   ROLES    AGE   VERSION
k8s-master01   Ready    master   10d   v1.15.1
k8s-node01     Ready    <none>   9d    v1.15.1
k8s-node02     Ready    <none>   9d    v1.15.1

由以上可以看到我部署Flannel以后, master检测到node节点 并且flannel容器显示Running正常

排查问题

[root@k8s-master01 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:2c:d1:c2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.50/24 brd 192.168.0.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe2c:d1c2/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:1f:d8:95:21 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
4: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether ee:02:3a:98:e3:e