My name is Joe, I have deployed the Kubernetes Cluster with nodes which is consisted 3 masters/workers and 2 workers as below. However, I have observed something related to networking in this Kubernetes cluster - Is there any concern of Kubernetes master/worker under different subnets.
I have been searching for this problem in Kubernetes community, unfortunately, I cannot find any answer in the community (Kubernetes Multi Master Cluster in different subnets).
[root@node1 ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION node1 Ready master,node 283d v1.12.1 node2 Ready master,node 283d v1.12.1 node3 Ready master,node 283d v1.12.1 node4 Ready node 282d v1.12.1 node5 Ready node 282d v1.12.1
IP address of each node
# Ansible inventory hosts BEGIN 192.168.0.11 node1 node1.cluster.local 192.168.200.15 node2 node2.cluster.local 192.168.0.13 node3 node3.cluster.local 192.168.200.14 node4 node4.cluster.local 192.168.0.24 node5 node5.cluster.local [root@node1 ~]# traceroute 192.168.200.15 traceroute to 192.168.200.15 (192.168.200.15), 30 hops max, 60 byte packets 1 192.168.0.1 (192.168.0.1) 0.983 ms 0.886 ms 0.833 ms 2 node2 (192.168.200.15) 0.477 ms !X 0.482 ms !X 0.503 ms !X
As said before, there are total 5 nodes in this cluster consisted by 3 master and 5 workers. It is observed that node1,node3 and node5 is under the subnet of 192.168.0.1/24 while node2 and node4 is under the subnet of 192.168.200.1/24. That i mean that the cluster is under different network segment.
[root@node1 ~]# ifconfig -a cali0d42f86e3d4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet6 fe80::ecee:eeff:feee:eeee prefixlen 64 scopeid 0x20<link> ether ee:ee:ee:ee:ee:ee txqueuelen 0 (Ethernet) RX packets 253525103 bytes 182266967754 (169.7 GiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 295104540 bytes 84587194290 (78.7 GiB) TX errors 0 dropped 3582 overruns 0 carrier 0 collisions 0
After that, I have there is a little bit packet drooped under one of cali virutal network interface. Thus, is there any uncertainty with the cluster node under different subnet?
Kubernetes version: v1.12.1
Docker version: 18.06.1-ce
Cloud being used: N/A (private)
Installation method: kubespray
Host OS: Red Hat Enterprise Linux Server release 7.5 (Maipo)
CNI and version: 0.3.1