SnapGear 1.7.8 Manuel D’Utilisation

7.  Virtual Private Networking  

Virtual Private Networking (VPN) enables two or more locations to communicate securely 
and effectively, usually across a public network (e.g. the Internet) and has the following 
key traits: 

•  Privacy - no one else can see what you are communicating  

•  Authentication - you know who you are communicating with 

•  Integrity - no one else can tamper with your messages/data 

Using VPN, you can access the office network securely across the Internet using Point-
to-Point Tunneling Protocol  (PPTP) or IPSec. If you take your portable computer on a 
business trip, you can dial a local number to connect to your Internet access provider and 
then create a second connection (called a “tunnel”) into your office network across the 
Internet and have the same access to your corporate network as if you were connected 
directly from your office. Similarly, telecommuters can also set up a VPN tunnel over their 
cable modem or DSL links to their local ISP. 

With the SnapGear appliance you can establish a secure VPN over the Internet using 
either PPTP or IPSec. IPSec provides better security; however PPTP is the preferred 
protocol for integrating with existing Microsoft infrastructure. The SnapGear appliance 
provides a PPTP server to enable remote Windows clients to securely access your office 
network. Using the SnapGear appliance’s PPTP client or IPSec you can also connect 
your office network to one or more remote networks.  

This chapter explains how to configure the PPTP server and client, as well as IPSec, in 
your SnapGear appliance and how to set up remote clients to connect to your VPN tunnel 
as shown in the following figure: