Book Image

Openswan: Building and Integrating Virtual Private Networks

By : Ken Bantoft, Paul Wouters
Book Image

Openswan: Building and Integrating Virtual Private Networks

By: Ken Bantoft, Paul Wouters

Overview of this book

<p>With the widespread use of wireless and the integration of VPN capabilities in most modern laptops, PDA's and mobile phones, there is a growing desire for encrypting more and more communications to prevent eavesdropping. Can you trust the coffee shop's wireless network? Is your neighbor watching your wireless? Or are your competitors perhaps engaged in industrial espionage? Do you need to send information back to your office while on the road or on board a ship? Or do you just want to securely access your MP3's at home? IPsec is the industry standard for encrypted communication, and Openswan is the de-facto implementation of IPsec for Linux.</p> <p>Whether you are just connecting your home DSL connection with your laptop when you're on the road to access your files at home, or you are building an industry size, military strength VPN infrastructure for a medium to very large organization, this book will assist you in setting up Openswan to suit those needs.</p> <p>The topics discussed range from designing, to building, to configuring Openswan as the VPN gateway to deploy IPsec using Openswan. It not only for Linux clients, but also the more commonly used Operating Systems such as Microsoft Windows and MacOSX. Furthermore it discusses common interoperability examples for third party vendors, such as Cisco, Checkpoint, Netscreen and other common IPsec vendors.</p> <p>The authors bring you first hand information, as they are the official developers of the Openswan code. They have included the latest developments and upcoming issues. With experience in answering questions on a daily basis on the mailing lists since the creation of Openswan, the authors are by far the most experienced in a wide range of successful and not so successful uses of Openswan by people worldwide.</p>
Table of Contents (22 chapters)
Building and Integrating Virtual Private Networks with Openswan
Credits
About the Authors
Acknowledgements
About the Reviewers
Preface

Advanced OE Setups


A good system administrator usually uses separate IP addresses for separate services. When a service, such as a web server, mail server, or DNS server, is moved to another physical computer, the IP address moves along with it, and the transition happens smoothly without interruption. There are of course many other reasons why a server can have more than one IP address, but nevertheless many hosts on the Internet have multiple IP addresses.

Sometimes it can be desirable to exclude some IP addresses from OE, but to enable OE for the other IP addresses. For instance, a very busy DNS server may not have the resources to initiate OE for all incoming requests, but if that same server is an email server, you might wish to protect all outgoing SMTP connections using OE. This can be done, using the (old-style) IP aliases. The following is an example configuration for such a scenario:

config setup
    interfaces="ipsec0=eth0 ipsec1=eth0:2 ipsec2=eth0:3"
conn eth0_2-to-anyone
   ...