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

Pitfalls of Debugging IPsec


Before we start our first configuration, you need to understand the security provided with a properly (and even improperly!) configured IPsec tunnel. To protect against various types of attacks, such as spoofing attacks, an IPsec peer that has been configured to talk to a remote host using IPsec will not talk to that peer without encryption, except for those packets needed to set up the IPsec tunnel, such as IKE packets.

If you are configuring IPsec, you are normally working locally on one endpoint, and have one remote endpoint. A secure login, usually using SSH, is used to configure the remote endpoint from the local one. Once both ends are configured, the IPsec subsystem can be started on both sides.

So imagine what happens if you made a mistake on the remote endpoint. The IPsec tunnel will fail to establish. It will refuse all cleartext packets from the local endpoint except IKE. This means you can no longer log in to the remote endpoint using SSH to fix its...