Understanding Kubernetes networking, pods with same ip

1
votes

I checked the pods in the kube-system namespace and noticed that some pods share the same ip address.The pods that share the same ip address appear to be on the same node.

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In the Kubernetes documenatation it said that "Evert pod gets its own ip address." (https://kubernetes.io/docs/concepts/cluster-administration/networking/). I'm confused as to how same ip for some pods came about.

1
kubernetes

1 Answers

3
votes

This was reported in issue 51322 and can depend on the network plugin you are using.

The issue was seen when using the basic kubenet network plugin on Linux.

Sometime, a reset/reboot can help

I suspect nodes have been configured with overlapped podCIDRs for such cases.
The pod CIDR could be checked by kubectl get node -o jsonpath='{.items[*].spec.podCIDR}'