title: How does dig query id work?
body: <p>How is the dig query id calculated or is it random?</p>
  
  <p>Specifically </p>
  
  <pre><code>$ dig google.co.uk
  
  ; &lt;&lt;&gt;&gt; DiG 9.11.0-P3 &lt;&lt;&gt;&gt; google.co.uk
  ;; global options: +cmd
  ;; Got answer:
  ;; -&gt;&gt;HEADER&lt;&lt;- opcode: QUERY, status: NOERROR, id: 63375
  </code></pre>
  
  <p>id: 63375
  What's its significance? If it is random then whats the point of it?</p>
  
  <hr>
  
  <p>The whole reason I'm writing this is because I honestly couldn't find much details about it on Google. So apologies for the quality of the question. </p>