我正在寻求帮助以解决这种无法正常工作的基本情况：
在MacBook上运行的VirtualBox VM上的kubeadm上安装了三个节点：
sudo kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubernetes-master Ready master 4h v1.10.2
kubernetes-node1 Ready <none> 4h v1.10.2
kubernetes-node2 Ready <none> 34m v1.10.2
Virtualbox VM具有2个适配器：1）仅主机2）NAT。来宾计算机的节点IP为：
kubernetes-master (192.168.56.3)
kubernetes-node1 (192.168.56.4)
kubernetes-node2 (192.168.56.5)
我正在使用法兰绒荚网（我之前也尝试过Calico，结果相同）。
安装主节点时，我使用了此命令：
sudo kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.56.3
我部署了一个Nginx应用程序，其Pod已启动，每个节点一个Pod：
nginx-deployment-64ff85b579-sk5zs 1/1 Running 0 14m 10.244.2.2 kubernetes-node2
nginx-deployment-64ff85b579-sqjgb 1/1 Running 0 14m 10.244.1.2 kubernetes-node1
我将它们作为ClusterIP服务公开：
sudo kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 22m
nginx-deployment ClusterIP 10.98.206.211 <none> 80/TCP 14m
现在是问题：
我使用ssh进入kubernetes-node1并使用群集IP卷曲服务：
ssh 192.168.56.4
---
curl 10.98.206.211
有时请求可以正常进行，返回nginx欢迎页面。我在日志中看到，该请求始终由同一节点（kubernetes-node1）中的pod回答。其他一些请求将被阻塞，直到超时。我猜这是发送到另一个节点（kubernetes-node2）中的pod。
反之亦然，当ssh进入kubernetes-node2时，来自该节点的pod记录成功的请求，而其他节点则超时。
我似乎存在某种网络问题，节点无法访问其他节点的Pod。我该如何解决？
UPDATE：
我将副本数缩减为1，因此kubernetes-node2上只有一个Pod
如果我将ssh放入kubernetes-node2，所有的卷发都会很好。在kubernetes-node1中时，所有请求都超时。
UPDATE 2：
kubernetes-master ifconfig
cni0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet 10.244.0.1 netmask 255.255.255.0 broadcast 0.0.0.0
inet6 fe80::20a0:c7ff:fe6f:8271 prefixlen 64 scopeid 0x20<link>
ether 0a:58:0a:f4:00:01 txqueuelen 1000 (Ethernet)
RX packets 10478 bytes 2415081 (2.4 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 11523 bytes 2630866 (2.6 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:cd:ce:84:a9 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.3 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::a00:27ff:fe2d:298f prefixlen 64 scopeid 0x20<link>
ether 08:00:27:2d:29:8f txqueuelen 1000 (Ethernet)
RX packets 20784 bytes 2149991 (2.1 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 26567 bytes 26397855 (26.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.3.15 netmask 255.255.255.0 broadcast 10.0.3.255
inet6 fe80::a00:27ff:fe09:f08a prefixlen 64 scopeid 0x20<link>
ether 08:00:27:09:f0:8a txqueuelen 1000 (Ethernet)
RX packets 12662 bytes 12491693 (12.4 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 4507 bytes 297572 (297.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
flannel.1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet 10.244.0.0 netmask 255.255.255.255 broadcast 0.0.0.0
inet6 fe80::c078:65ff:feb9:e4ed prefixlen 64 scopeid 0x20<link>
ether c2:78:65:b9:e4:ed txqueuelen 0 (Ethernet)
RX packets 6 bytes 444 (444.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 6 bytes 444 (444.0 B)
TX errors 0 dropped 15 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 464615 bytes 130013389 (130.0 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 464615 bytes 130013389 (130.0 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tunl0: flags=193<UP,RUNNING,NOARP> mtu 1440
tunnel txqueuelen 1000 (IPIP Tunnel)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethb1098eb3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet6 fe80::d8a3:a2ff:fedf:4d1d prefixlen 64 scopeid 0x20<link>
ether da:a3:a2:df:4d:1d txqueuelen 0 (Ethernet)
RX packets 10478 bytes 2561773 (2.5 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 11538 bytes 2631964 (2.6 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
kubernetes-node1 ifconfig
cni0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet 10.244.1.1 netmask 255.255.255.0 broadcast 0.0.0.0
inet6 fe80::5cab:32ff:fe04:5b89 prefixlen 64 scopeid 0x20<link>
ether 0a:58:0a:f4:01:01 txqueuelen 1000 (Ethernet)
RX packets 199 bytes 41004 (41.0 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 331 bytes 56438 (56.4 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:0f:02:bb:ff txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.4 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::a00:27ff:fe36:741a prefixlen 64 scopeid 0x20<link>
ether 08:00:27:36:74:1a txqueuelen 1000 (Ethernet)
RX packets 12834 bytes 9685221 (9.6 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9114 bytes 1014758 (1.0 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.3.15 netmask 255.255.255.0 broadcast 10.0.3.255
inet6 fe80::a00:27ff:feb2:23a3 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:b2:23:a3 txqueuelen 1000 (Ethernet)
RX packets 13263 bytes 12557808 (12.5 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5065 bytes 341321 (341.3 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
flannel.1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet 10.244.1.0 netmask 255.255.255.255 broadcast 0.0.0.0
inet6 fe80::7815:efff:fed6:1423 prefixlen 64 scopeid 0x20<link>
ether 7a:15:ef:d6:14:23 txqueuelen 0 (Ethernet)
RX packets 483 bytes 37506 (37.5 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 483 bytes 37506 (37.5 KB)
TX errors 0 dropped 15 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 3072 bytes 269588 (269.5 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 3072 bytes 269588 (269.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth153293ec: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet6 fe80::70b6:beff:fe94:9942 prefixlen 64 scopeid 0x20<link>
ether 72:b6:be:94:99:42 txqueuelen 0 (Ethernet)
RX packets 81 bytes 19066 (19.0 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 129 bytes 10066 (10.0 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
kubernetes-node2 ifconfig
cni0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 10.244.2.1 netmask 255.255.255.0 broadcast 0.0.0.0
inet6 fe80::4428:f5ff:fe8b:a76b prefixlen 64 scopeid 0x20<link>
ether 0a:58:0a:f4:02:01 txqueuelen 1000 (Ethernet)
RX packets 184 bytes 36782 (36.7 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 284 bytes 36940 (36.9 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:7f:e9:79:cd txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.5 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::a00:27ff:feb7:ff54 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:b7:ff:54 txqueuelen 1000 (Ethernet)
RX packets 12634 bytes 9466460 (9.4 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 8961 bytes 979807 (979.8 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.3.15 netmask 255.255.255.0 broadcast 10.0.3.255
inet6 fe80::a00:27ff:fed8:9210 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:d8:92:10 txqueuelen 1000 (Ethernet)
RX packets 12658 bytes 12491919 (12.4 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 4544 bytes 297215 (297.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
flannel.1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450
inet 10.244.2.0 netmask 255.255.255.255 broadcast 0.0.0.0
inet6 fe80::c832:e4ff:fe3e:f616 prefixlen 64 scopeid 0x20<link>
ether ca:32:e4:3e:f6:16 txqueuelen 0 (Ethernet)
RX packets 111 bytes 8466 (8.4 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 111 bytes 8466 (8.4 KB)
TX errors 0 dropped 15 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 2940 bytes 258968 (258.9 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2940 bytes 258968 (258.9 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
UPDATE 3：
Kubelet日志：
kubernetes-master kubelet logs
IP路由
Master
kubernetes-master:~$ ip route
default via 10.0.3.2 dev enp0s8 proto dhcp src 10.0.3.15 metric 100
10.0.3.0/24 dev enp0s8 proto kernel scope link src 10.0.3.15
10.0.3.2 dev enp0s8 proto dhcp scope link src 10.0.3.15 metric 100
10.244.0.0/24 dev cni0 proto kernel scope link src 10.244.0.1
10.244.1.0/24 via 10.244.1.0 dev flannel.1 onlink
10.244.2.0/24 via 10.244.2.0 dev flannel.1 onlink
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.56.0/24 dev enp0s3 proto kernel scope link src 192.168.56.3
Node1
kubernetes-node1:~$ ip route
default via 10.0.3.2 dev enp0s8 proto dhcp src 10.0.3.15 metric 100
10.0.3.0/24 dev enp0s8 proto kernel scope link src 10.0.3.15
10.0.3.2 dev enp0s8 proto dhcp scope link src 10.0.3.15 metric 100
10.244.0.0/24 via 10.244.0.0 dev flannel.1 onlink
10.244.1.0/24 dev cni0 proto kernel scope link src 10.244.1.1
10.244.2.0/24 via 10.244.2.0 dev flannel.1 onlink
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.56.0/24 dev enp0s3 proto kernel scope link src 192.168.56.4
Node2
kubernetes-node2:~$ ip route
default via 10.0.3.2 dev enp0s8 proto dhcp src 10.0.3.15 metric 100
10.0.3.0/24 dev enp0s8 proto kernel scope link src 10.0.3.15
10.0.3.2 dev enp0s8 proto dhcp scope link src 10.0.3.15 metric 100
10.244.0.0/24 via 10.244.0.0 dev flannel.1 onlink
10.244.1.0/24 via 10.244.1.0 dev flannel.1 onlink
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.56.0/24 dev enp0s3 proto kernel scope link src 192.168.56.5
iptables-save：
kubernetes-master iptables-save
我在使用Flannel的K8s群集中遇到了类似的问题。我已经为vms设置了NAT nic来实现Internet连接，并为Host-only nic设置了节点到节点的通信。 Flannel默认为节点到节点通信选择NAT nic，这显然在这种情况下不起作用。
我在部署之前修改了法兰绒清单以设置-iface = enp0s8应该选择的仅限主机nic的参数（在我的情况下为enp0s8）。在您的情况下，看来enp0s3是正确的NIC。之后，节点到节点的通信工作正常。
我没注意到我也修改了kube-proxy清单以包含-cluster-cidr = 10.244.0.0 / 16和 --proxy-mode = iptables似乎也是必需的。
用iptables --flush和iptables -tnat --flush刷新了所有防火墙，然后重启docker修复了它
基于您的日志以及您仅对使用Flannel的节点之间的连接存在问题的事实，我想您在安装过程中对Flannel CNI遇到了问题。
在node1和master的日志中，我看到以下消息：
Error adding network: open /run/flannel/subnet.env: no such file or directory
Error while adding to cni network: open /run/flannel/subnet.env: no such file or directory
根本原因可能是虚拟机之间的网络问题。
我建议您为群集中的每个实例创建2个网络-一个具有NAT的网络以访问Internet，而另一个则仅用于主机的集群内通信。
作为一种替代方法-如果网络允许，可以将Bridge模式用于VM的接口。
最后，我可以提供的唯一建议-使用上述配置，删除所有群集组件并再次初始化群集。那是最快的方法。
在带有绒布的raspberrypi群集上原始安装kubernetes之后，我遇到了相同的问题。
解决方案是禁用ufw防火墙。