title: How Network Monitoring System measure Network Traffic
body: <p>I'm going to develop a network monitoring system for my final year project in college. Before the development, I've gone through some research about how a network monitoring system works. From my understanding, network monitoring system used ICMP packet (Ping) to make sure the devices is "alive" in the network. Here is the problem I had:</p>
  
  <ol>
  <li><p>If network monitoring system need to ping each and every device in the network, then the network traffic will become heavy, is that good approach to use this method? Or is there any other possible alternative?</p></li>
  <li><p>Network monitoring system provide set of data of the network traffic, is that possible for the network monitoring system to get the traffic level for all the connection? Assume there are 3 PCs, PC X, PC Y, and PC Z.  PC X connected to PC Y, and PC Y connected to both of the PCs, PC X used for monitor the network, when PC Y sending packets to PC Z, is that possible that PC X get the information that PC Y is sending packets to PC Z?</p></li>
  </ol>
  
  <p>Thanks</p>