title: TCPDUM Bit Masking
body: <p>Reading 'GE' from tcp payload. Basically trying to ready GET for sake of keeping the filter short, using only 'GE' as it get the packet having GET keyword.</p>
  
  <p>Blow Filter with Bit Shifting works fine </p>
  
  <p><strong>"tcpdump -r tcpdump.pcap -nta 'tcp[((tcp[12] >> 4) * 4):2] = 0x4745'"</strong></p>
  
  <p>but i am not sure why below one not working</p>
  
  <p><strong>tcpdump -r file.pcap -nta 'tcp[((tcp[12] &amp; 0xf0 != 0) * 4):2] = 0x4745'</strong></p>
  
  <p>It will be a great help if someone can notify the problem. Thanks. </p>