<p><strong>Reproduce steps:</strong></p>

<ol>
<li><code>kubectl run busybox1 --generator=run-pod/v1 --image=busybox:1.28 -- sleep 3600</code></li>
<li><code>kubectl run busybox2 --generator=run-pod/v1 --image=busybox:1.31.1 -- sleep 3600</code></li>
<li><code>kubectl exec -ti busybox1 -- nslookup kubernetes.default</code></li>
</ol>

<p><strong>works fine</strong></p>

<blockquote>
  <p>Server:    10.96.0.10</p>
  
  <p>Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local</p>
  
  <p>Name:      kubernetes.default</p>
  
  <p>Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local</p>
</blockquote>

<ol start="4">
<li><code>kubectl exec -ti busybox2 -- nslookup kubernetes.default</code></li>
</ol>

<p><strong>not working</strong></p>

<blockquote>
  <p>Server:         10.96.0.10
     Address:        10.96.0.10:53</p>
  
  <p>** server can't find kubernetes.default: NXDOMAIN</p>
  
  <p>*** Can't find kubernetes.default: No answer</p>
  
  <p>command terminated with exit code 1</p>
</blockquote>

<p>does nslookup work differently on 1.31.1?</p>

<p>what's the correct way to use nslookup on 1.31.1?</p>

<p>DNS inside busybox only works correctly in images &lt;= 1.28.4. </p>

<p>Fixing the version <code>image: "busybox:1.28.0"</code> should do the trick. </p>

<p>There's a thread here <a href="https://github.com/kubernetes/kubernetes/issues/66924" rel="noreferrer">https://github.com/kubernetes/kubernetes/issues/66924</a></p>
