As promised, let me continue with my venture with VPN protocols. You will get to read a lot about different free VPN services around the Internet but hardly will people tell you how these VPN services function. It is when you understand the technicalities hidden behind these VPN services, that you are able to choose for the best VPN service for yourself. Learn about the L2TP protocol.

Other VPN protocols that I have already discussed (list will be updated as and when new articles are written):

NOTE: Remember to read these in the order given above so that you understand them more clearly.

Today, we will throw some light on the Layer 2 Tunneling Protocol which is also called L2TP in short. This protocol was created in coordination with the likes of Microsoft and Cisco. Layer 2 Tunneling Protocol was actually a combination of two different protocols given below:

  • Layer 2 Forwarding (L2F) protocol owned and developed by Cisco.
  • Point-to-Point tunneling protocol owned and developed by Microsoft.

L2TP had several advantages that made it shine when compared to PPTP. One of the most important of these advantages was its usage over non-IP networks such as frame relay, X.25, and ATM. L2TP, like PPTP, operates over the data link layer in the very famous OSI network model. Also, most of the major firewalls like WatchGuard, Cisco PIX, CheckPoint, and ISA server support L2TP without any hitches.

The Windows-based 2003, XP and 2000 carry the built-in client for L2TP. If you are one of the legacy Windows users who are still using older versions of Windows (like Windows 98, NT4.0 or ME) then you can download clients that support L2TP.

L2TP uses the features provided by IP Sec (IP security) and its enhanced form namely ESP (Encapsulating Security Payload) protocol to secure its connections. It also requires the use of digital certificates f