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).New features in the second edition include SSH, which is a popular VPN solution for Unix systems, and an expanded description of the IPSec standard, for which several vendors have announced support.Topics include:
How the VPN compares to other available networking technologies
Introduction to encryption, firewalls, the IPSec standard, and other technologies that let VPNs work
Point to Point Tunneling Protocol (PPTP) and L2TP
The Altavista Tunnel
The Cisco PIX Firewall
Secure Shell (SSH)
Maintenance and troubleshooting
Chapter 1 Why Build a Virtual Private Network?
What Does a VPN Do?
Security Risks of the Internet
How VPNs Solve Internet Security Issues
A Note on IP Address and Domain Name Conventions Used in This Book
Chapter 2 Basic VPN Technologies
Encryption and Authentication
Methodologies for Compromising VPNs
Patents and Legal Ramifications
Chapter 3 Wide Area, Remote Access, and the VPN
General WAN, RAS, and VPN Concepts
VPN Versus WAN
VPN Versus RAS
Chapter 4 Implementing Layer 2 Connections
Differences Between PPTP, L2F, and L2TP
How PPTP Works
Features of PPTP
Chapter 5 Configuring and Testing Layer 2 Connections
Installing and Configuring PPTP on a Windows NT RAS Server
Configuring PPTP for Dial-up Networking on a Windows NT Client
Configuring PPTP for Dial-up Networking on a Windows 95 or 98 Client
Enabling PPTP on Remote Access Switches
Making the Calls
Using PPTP with Other Security Measures
Chapter 6 Implementing the AltaVista Tunnel 98
Advantages of the AltaVista Tunnel System
AltaVista Tunnel Limitations
How the AltaVista Tunnel Works
VPNs and AltaVista
Chapter 7 Configuring and Testing the AltaVista Tunnel
Installing the AltaVista Tunnel
Configuring the AltaVista Tunnel Extranet and Telecommuter Server
Configuring the AltaVista Telecommuter Client
Chapter 8 Creating a VPN with the Unix Secure Shell
Charlie has also coauthored a half-dozen Internet-related books (many with Mike and Paul), on topics ranging from electronic commerce to CGI programming. When he finds spare time, Charlie likes to write (as of yet unpublished) fiction, read, and go to the gym. He also enjoys spending time with his wife, Mary, and their four beautiful felines. Mike Erwin is the president and chief executive officer of OuterNet Connection Strategies, Inc. Mike has served these posts for the last four years, during which he also worked for Apple Computer, Inc., architecting and implementing connectivity, application, scripting, and development support for Apple's Worldwide Support Center. Mike is the coauthor of several other works, including the CGI Bible, Building Web Commerce Sites, and the 60 Minute Guide to VRML. Mike's technology related interests involve encryption algorithms, super computing, Distributed Operating Systems, universe game simulations, and building secondary securities markets on the Net. Before becoming completely immersed in work, Mike used to find that his hobbies included playing hearts, drinking cheap vodka, staying up until dawn, and doodling with oil paints with his left hand. Mike's current favorite things include dabbling with theoretical and particle physics, martial arts training, gambling, securities prospecting, and, of course, sleeping.
Charlie Scott is the senior vice president of OuterNet Connection Strategies, Inc., an Internet Service Provider and outsource company based in Austin, Texas, specializing in innovative and emergent technologies. At OuterNet, he helps create and implement new products for their network operations center and co-location facilities. While an undergraduate at the University of Texas at Austin, Charlie was a research assistant in a cognitive science lab, and planned on going to graduate school in that field. He was eventually able to get his B.A. in psychology. But he always enjoyed working with computers, and his exposure to the Internet at UT deviated him enough to abandon all plans for graduate school and start working with computer networks. The next few years saw him at Texas Instruments, IBM, and Wayne-Dresser before he helped found OuterNet. Charlie has also coauthored a half-dozen Internet-related books (many with Mike and Paul), on topics ranging from electronic commerce to CGI programming. When he finds spare time, Charlie likes to write (as of yet unpublished) fiction, read, and go to the gym. He also enjoys spending time with his wife, Mary, and their four beautiful felines.
Charlie has also coauthored a half-dozen Internet-related books (many with Mike and Paul), on topics ranging from electronic commerce to CGI programming. When he finds spare time, Charlie likes to write (as of yet unpublished) fiction, read, and go to the gym. He also enjoys spending time with his wife, Mary, and their four beautiful felines. Paul Wolfe has done everything from driving M1A1 tanks in Desert Storm to slinging computer chips for Motorola. He now divides his time between his family and OuterNet, as well as writing. He has written four books in the last two years covering such topics as Windows NT Web servers, Internet commerce, VRML, and Virtual Private Networks. He dreams of restoring his 1986 Toyota Tercel to its former glory and racing it on the stock car circuit.
Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects. The animals featured on the cover of Virtual Private Networks are puffins. Puffins are small, unusual-looking birds with large triangular bills, short necks, and stocky bodies. They live in colonies, sometimes tens of thousands of birds together, along the icy shores of the northern regions of the globe. Though rarely seen outside of the northern regions, there are approximately 15 million puffins in the world today. Despite their short wings, puffins can fly, although they spend most of their time swimming or walking erect on land. While flying they make a purring sound.
Here's some more puffin stuff: Puffins' primary food sources are small fish and marine animals. They dive for fish and use their wings to swim underwater to catch them. They can carry as many as 30 fish in their mouth at one time, to bring back to shore for their young. Puffin pairs often mate for life. Usually one egg is laid per pair, and both mother and father incubate the egg and feed the young hatchling. Edie Freedman designed the cover of this book, using a 19th-century engraving from the Dover Pictorial Archive. The cover layout was produced with Quark XPress 3.3 using the ITC Garamond font. Whenever possible, our books use RepKover™, a durable and flexible lay-flat binding. If the page count exceeds RepKover™s limit, perfect binding is used.
The inside layout was designed by Nancy Priest and implemented in FrameMaker by Mike Sierra. The text and heading fonts are ITC Garamond Light and Garamond Book. The illustrations that appear in the book were created in Macromedia Freehand 7.0 and screen shots were created in Adobe Photoshop 4.0 by Robert Romano. This colophon was written by Clairemarie Fisher O'Leary.