title: What is the relationship between the port type and the symmetric type returned by stunclient？
body: <p>Running the stun command you can see that the description returned will indicate whether the port is a <code>preserves port</code> or a <code>random port</code> and that b0 will also indicate whether it is a <code>preserves port</code> or a <code>random port</code>.
  And b3 is a description of whether the NAT type is symmetric or not symmetric?
  As I understand it, all Cone type NATs are <code>preserves port</code> and all symmetric type ones are <code>random port</code>. Isn't this a duplicate description?</p>
  <p>Can someone tell me what exactly is the difference between these two?</p>