kubectl exec -it etcd-0 sh
/ # nslookup etcd.default
nslookup: can't resolve '(null)': Name does not resolve
Name: etcd.default
Address 1: 172.30.243.197 etcd-2.etcd.default.svc.cluster.local
Address 2: 172.30.243.246 etcd-1.etcd.default.svc.cluster.local
Address 3: 172.30.243.255 etcd-0.etcd.default.svc.cluster.local
/ # nslookup www.google.com
nslookup: can't resolve '(null)': Name does not resolve
nslookup: can't resolve 'www.google.com': Try again
kubectl version
Client Version: version.Info{Major:"1", Minor:"9", GitVersion:"v1.9.6", GitCommit:"9f8ebd171479bec0ada837d7ee641dec2f8c6dd1", GitTreeState:"clean", BuildDate:"2018-03-21T15:21:50Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"9", GitVersion:"v1.9.6", GitCommit:"9f8ebd171479bec0ada837d7ee641dec2f8c6dd1", GitTreeState:"clean", BuildDate:"2018-03-21T15:13:31Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}
kubectl describe svc kube-dns -n kube-system
Name: kube-dns
Namespace: kube-system
Labels: addonmanager.kubernetes.io/mode=Reconcile
k8s-app=kube-dns
kubernetes.io/cluster-service=true
kubernetes.io/name=KubeDNS
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"addonmanager.kubernetes.io/mode":"Reconcile","k8s-app":"kube-dns","kubernet...
Selector: k8s-app=kube-dns
Type: ClusterIP
IP: 10.254.0.2
Port: dns 53/UDP
TargetPort: 53/UDP
Endpoints: 172.30.243.253:53
Port: dns-tcp 53/TCP
TargetPort: 53/TCP
Endpoints: 172.30.243.253:53
Session Affinity: None
Events: <none>