title: tcpdump capture traffics on kaa server
body: <p>I have a device with kaa C sdk that is connected with a kaa server.  The devices and kaa server communications work well, I could see the data of the device was uploaded regularly to mongo DB on the kaa server. However, when tried to use tcpdump to capture the traffic on the server, I could not get any packets from the device.</p>
  
  <p>So wondering what I missed. Anything special needs be taken cared to capture networking packets of kaa devices?</p>
  
  <p>Thanks,
  Paul</p>