title: Prefered network interface of Socket.bind
body: <p><a href="http://docs.oracle.com/javase/tutorial/networking/nifs/definition.html" rel="nofollow">http://docs.oracle.com/javase/tutorial/networking/nifs/definition.html</a>
  says "When you create the socket and bind it to that address, the system uses the associated interface". I tried to do the example on the page on Linux and Android system, however it doesn't work so on both. The bound IP address is set to source IP address on the IP header but the transmitting interface does NOT still change. Many persons referred to the URL on Stack Overflow. Does it work so really?</p>