title: Is "man in middle" possible for VPN during the first time client connect to the server?
body: <p>According to <a href="http://en.wikipedia.org/wiki/Secure_Shell#Key_management" rel="nofollow">http://en.wikipedia.org/wiki/Secure_Shell#Key_management</a>, ssh is vulnerable to "man-in-the-middle" attack when establishing the first connection with server.</p>
  
  <blockquote>
    <p>SSH also supports password-based authentication that is encrypted by automatically generated keys. In this case the attacker could imitate the legitimate side, ask for the password and obtain it (man-in-the-middle attack). However this is only possible if the two sides have never authenticated before, as SSH remembers the key that the remote side once used.</p>
  </blockquote>
  
  <p>Does VPN suffer from the same "weakness"?</p>