Historically, only large companies could afford secure networks, which
they created from expensive leased lines. Smaller folks had to make do
with the relatively untrusted Internet. Nowadays, even large companies
have to go outside their private nets, because so many people
telecommute or log in while they're on the road. How do you provide a
low-cost, secure electronic network for your organization?
The
solution is a virtual private network: a collection of technologies
that creates secure connections or "tunnels" over regular Internet
lines--connections that can be easily used by anybody logging in from
anywhere. A number of products now exist to help you develop that
solution.
This book tells you how to plan and build a VPN. It
starts with general concerns like costs, configuration, and how a VPN
fits in with other networking technologies like firewalls. It continues
with detailed descriptions of how to install and use VPN technologies
that are available for Windows NT and Unix, such as PPTP and L2TP,
Altavista Tunnel, Cisco PIX, and the secure shell (SSH).
