Cannot Ping Pod on another Node

General Discussions
1

Cluster information:

Kubernetes version: 1.26.15
Cloud being used: (put bare-metal if not on a public cloud)
Installation method: AWS-hosted servers
Host OS: RHEL 8
CNI and version: Flannel

I recently created 4 node cluster (1 control plane) with default CIDR for flannel - 10.244.0.0/16, enabled firewall with required ports.

All flannel pods are running healthy and there is cni0 link present on all the nodes.

However, i’m not able to ping pod running on another node, but able to ping pod on same node.

There is communication between nodes as well when pinged and curl (port:6443)

Can you help me urgently what I need to look after?

The pods that I’m testing are dummy pods - busybox and nginx.

2

check: need to confirm the flannel backend mode.
need UDP/8472

kubectl -n kube-flannel get cm kube-flannel-cfg -o yaml

3

8472 is allowed and I can see entries in iptable/firewall list. infact all the ports are open between the nodes