title: Parsing data on 4th Octet
body: <p>I have large files over 1 GB each.</p>
  
  <p>They include 3 fields per record (tab delimited).</p>
  
  <pre><code>Src IP (tab) Dst IP (tab) DNS query
  1.1.1.1 (tab) 2.2.2.2 (tab) test.com
  1.2.3.1 (tab) 1.2.3.4 (tab) test.com
  1.2.4.1 (tab) 9.8.7.6 (tab) bing.com
  1.1.1.2 (tab) 2.2.2.2 (tab) test.com
  9.8.7.2 (tab) 2.2.2.2 (tab) test.com
  3.3.3.2 (tab) 2.2.2.2 (tab) bing.com
  </code></pre>
  
  <p>I would like to use AWK to count and list all DNS queries per the 4th octet of the src IP only. Thus output for above would look like the following:</p>
  
  <pre><code>4th octet (tab) DNS query (tab) count
  .1 (tab) test.com (tab) 2
  .1 (tab) bing.com (tab) 1
  .2 (tab) test.com (tab) 1
  .2 (tab) bing.com (tab) 2
  </code></pre>
  
  <p>I don't care about either the 1st, 2nd or 3rd octet of the Src IP address nor any part of the Dest IP address.</p>
  
  <p>Only looking for a list of all DNS Queries with count per 4th octet of Src IP.</p>
  
  <p>FWIW</p>