<p>I have kubernetes cluster running on <code>Ubuntu 16.04</code>. When I run <code>nslookup kubernetes.default</code> on <code>master</code> it shows below:</p>

<pre><code>Server:     192.168.88.21
Address:    192.168.88.21#53

** server can't find kubernetes.default: NXDOMAIN
</code></pre>

<p>Below is the content of <code>/etc/resolv.conf</code></p>

<pre><code># Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

nameserver 192.168.88.21
nameserver 127.0.1.1
search VISDWK.local
</code></pre>

<p>Using kubernetes version</p>

<pre><code>kubeadm version: &amp;version.Info{Major:"1", Minor:"13", GitVersion:"v1.13.1", GitCommit:"eec55b9ba98609a46fee712359c7b5b365bdd920", GitTreeState:"clean", BuildDate:"2018-12-13T10:36:44Z", GoVersion:"go1.11.2", Compiler:"gc", Platform:"linux/amd64"}
</code></pre>

<p>Using weave for networking and installed using:</p>

<pre><code>kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
</code></pre>

<p><code>coredns</code> pods are running fine:</p>

<pre><code>coredns-86c58d9df4-42xqc               1/1     Running   8         1d6h
coredns-86c58d9df4-p6d98               1/1     Running   7         1d1h
</code></pre>

<p>Below are the logs of <code>coredns-86c58d9df4-42xqc</code></p>

<p><code>.:53
2019-02-08T08:40:10.038Z [INFO] CoreDNS-1.2.6
2019-02-08T08:40:10.039Z [INFO] linux/amd64, go1.11.2, 756749c
CoreDNS-1.2.6
linux/amd64, go1.11.2, 756749c
 [INFO] plugin/reload: Running configuration MD5 = f65c4821c8a9b7b5eb30fa4fbc167769
t</code></p>

<p>Can anyone please help me debug this issue. Please help. Thanks.</p>

<p>something wrong with busybox image. it works but am getting some errors after the nslookup command is run</p>
<pre><code>[node1 ~]$ kubectl run busybox1 --image busybox --restart=Never --rm -it -- sh
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server:         10.96.0.10
Address:        10.96.0.10:53

Name:   kubernetes.default.svc.cluster.local
Address: 10.96.0.1

*** Can't find kubernetes.svc.cluster.local: No answer
*** Can't find kubernetes.cluster.local: No answer
*** Can't find kubernetes.default.svc.cluster.local: No answer
*** Can't find kubernetes.svc.cluster.local: No answer
*** Can't find kubernetes.cluster.local: No answer
/ # exit
pod &quot;busybox1&quot; deleted
[node1 ~]$
</code></pre>
<p>try with below image. it works perfectly. other versions are throwing some errors</p>
<h1>busybox:1.28</h1>
<pre><code>[node1 ~]$ kubectl run busybox1 --image busybox:1.28 --restart=Never --rm -it -- sh
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
/ # exit
pod &quot;busybox1&quot; deleted
</code></pre>
<h1>Test the api server from master</h1>
<pre><code>[node1 ~]$ kubectl get svc|grep kubernetes
kubernetes      ClusterIP      10.96.0.1      &lt;none&gt;        443/TCP          2h
[node1 ~]$
[node1 ~]$ curl -k https://10.96.0.1/version
{
  &quot;major&quot;: &quot;1&quot;,
  &quot;minor&quot;: &quot;11&quot;,
  &quot;gitVersion&quot;: &quot;v1.11.7&quot;,
  &quot;gitCommit&quot;: &quot;65ecaf0671341311ce6aea0edab46ee69f65d59e&quot;,
  &quot;gitTreeState&quot;: &quot;clean&quot;,
  &quot;buildDate&quot;: &quot;2019-01-24T19:22:45Z&quot;,
  &quot;goVersion&quot;: &quot;go1.10.7&quot;,
  &quot;compiler&quot;: &quot;gc&quot;,
  &quot;platform&quot;: &quot;linux/amd64&quot;
}[node1 ~]$
</code></pre>
