title: What's the point of using L2TP together with IPSec?
body: <p>According to my limited understanding, IPSec authenticates peers and encapsulates/encrypts IP packets in tunnel mode.</p>
  
  <p>On another hand, L2TP itself does not offer authentication/encryption, but offers encapsulation, which is already achieved by IPSec.</p>
  
  <p>In my application, I would like to secure end-to-end data transfer using IPSec. I am also considering "L2TP/IPSec" but cannot figure out which L2TP feature is not offered by IPSec? Why would I choose to use L2TP/IPSec rather than IPSec alone?</p>