Blog: Kubernetes Networking Internals

General Discussions
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Get an overview of Kubernetes networking internals from this article https://blog.calsoftinc.com/2017/03/kubernetes-networking-internals.html

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Some basics for Quick Checks

ip link
ip link | grep ens3
ip link show ens3
arp node
ip route show default
netstat -nplt
netstat -anp | grep etcd

ps -aux | grep kubelet
ps -aux | grep kube-api
ls /etc/cni/net.d/

kubectl logs weave -n kube-system
kubectl logs -n kube-system

kubectl run test --restart=Never --image=busybox:1.28 --rm -it – nslookup nginx-resolver-service

1 Like
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check current policy
kubectl describe netpol

kubectl run --generator=run-pod/v1 test-np --image=busybox:1.28 --rm -it – sh
nc -z -v -w 2 np-test-service 80

test if a service is up

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Check process/service:
netstat -plnt | grep PortNumber
or
lsof -i :PortNumber

Use systemctl to check/start/stop/disable/enable service:
systemctl status serviceName