title: Why the python-tcpdum command can't capture packet in a file
body: <p>I have the following TcpDump command written in Python but it doesn't give me any output file with the requested packets although I have TcpDump installed and tested on my Ubuntu VM :</p>
  
  <pre><code>    command = 'sudo /usr/sbin/tcpdump -i eth1 {} -c {} -s 0  -w {}'\
              .format( 'tcp host 10.0.2.15','30000',
                      '/home/results/xyz.pcap')
  </code></pre>