title: IP masquerading, what if the router runs out of ports?
body: <p>I have recently discovered ip masquerading.</p>
  
  <p>My question is simple: if routers actually map hosts ports to their own ports, what if they run out of ports ? Suppose the network has got 4 hosts on IPs 192.168.0.{2,3,4,5}, each using 20000 ports, how does a router map 80000 ports to his 65000.</p>
  
  <p>Although I couldn't find any information on this, I am guessing masquerading occurs on traffic only, thus there shouldn't be 20k ports to map per host, but why not ? I can't figure it out.</p>