title: connect to connect to pptp vpn just using terminal
body: <p>I want to create a pptp vpn client and connect to it using terminal. 
  I created a connection using <code>pptp-setup</code> and then connect to it using ‍<code>pon‍‍</code> command. 
  but the problem is my internet traffic does'nt route through this vpn connection.</p>