title: Monitoring multiple ports in tcpdump
body: <p>I am trying to find a way to read multiple ports using tcpdump. Suppose I have two ports,  p1 and p2, and I want to read the traffic moving through both ports simultaneously. Is there any way to do it using tcpdump or will I have to use some other tool?</p>
  
  <p>Basically I am running a proxy server which is running on some port. I want to read the traffic moving through this port as well traffic moving through port 80(HTTP).</p>