Networking

Question 1

What linux command will show you the ports that a service is listening on?

Answer 1

netstat -nplt

Question 2

What linux command shows the connections to a port?

Answer 2

netstat -anp | grep etcd

Question 3

What is the default port for the kube-api service?

Answer 3

6443

Question 4

What is the default port for the kube-scheduler?

Answer 4

10259

Question 5

What is the default port for the kube-controller-manager?

Answer 5

10257

Question 6

What is the default port for the etcd server?

Answer 6

2379

Question 7

What is the default port for the etcd server communications on multiple master nodes?

Answer 7

2380

Question 8

What port does the kubelet listen to on each node?

Answer 8

10250

Question 9

What port do the workder nodes listen to for services?

Answer 9

30000-32767

Question 10

What service configures the CNI?

Answer 10

kubelet

Question 11

What is the linux command to check the kubelet config?

Answer 11

ps -aux | grep kubelet

Question 12

How would you check for CNI plugins?

Answer 12

ps -aux | grep kubelet
ls <path></path>

Question 13

How would you check the CNI config?

Answer 13

ls /etc/cni/net.d

Question 14

What path does CNI store it’s plugins?

Answer 14

/opt/cni/bin

Question 15

What is the directory where CoreDNS stores it’s config file?

Answer 15

/etc/coredns/Corefile

Question 16

How is the Corefile passed into the CoreDNS POD?

Answer 16

The conf file is passed to the nodes as a configmap object kubectl get configmap -n kube-system

Question 17

What is the command to get ingresses?

Answer 17

k get ingress

*Generally you would want to specify -A for all namespaces