VPNs Illustrated: Tunnels, VPNs, and IPsec (Paperback)

Description

Virtual private networks (VPNs) based on the Internet instead of the traditional leased lines offer organizations of all sizes the promise of a low-cost, secure electronic network. However, using the Internet to carry sensitive information can present serious privacy and security problems. By explaining how VPNs actually work, networking expert Jon Snader shows software engineers and network administrators how to use tunneling, authentication, and encryption to create safe, effective VPNs for any environment.

Using an example-driven approach, VPNs Illustrated explores how tunnels and VPNs function by observing their behavior "on the wire." By learning to read and interpret various network traces, such as those produced by tcpdump, readers will be able to better understand and troubleshoot VPN and network behavior.

Specific topics covered include:

• Block and stream symmetric ciphers, such as AES and RC4; and asymmetric ciphers, such as RSA and EIGamal
• Message authentication codes, including HMACs
• Tunneling technologies based on gtunnel
• SSL protocol for building network-to-network VPNs
• SSH protocols as drop-in replacements for telnet, ftp, and the BSD r-commands
• Lightweight VPNs, including VTun, CIPE, tinc, and OpenVPN
• IPsec, including its Authentication Header (AH) protocol, Encapsulating Security Payload (ESP), and IKE (the key management protocol)

Packed with details, the text can be used as a handbook describing the functions of the protocols and the message formats that they use. Source code is available for download, and an appendix covers publicly available software that can be used to build tunnels and analyze traffic flow.

VPNs Illustrated gives you the knowledge of tunneling and VPN technology you need to understand existing VPN implementations and successfully create your own.

Table of Contents

Preface.

I. BACKGROUND.

1. Introduction.

    Purpose

    Readers

    Typographical Conventions

    Source Code and Third-Party Programs

    Testbed

    Road Map

    Summary

2. TCP/IP Overview.

    Introduction

    Layering

    Encapsulation

    Addressing

    IP

    UDP

    TCP

    ICMP

    NAT and Private IP Addresses

    PPP

    IPv6

    Routing

    Summary

    Exercises

3. Cryptography Overview.

    Introduction

    Symmetric Ciphers

    Asymmetric Ciphers

    Cryptographic Hash Functions, MACs, and HMACs

    Digital Signatures

    Certificates

    Summary

    Exercises

4. Tunnels.

    Introduction

    IP-in-IP Tunnels

    PPPoE

    GRE

    PPTP

    L2TP

    MPLS

    gtunnel

    Summary

    Exercises

II. TUNNELS AND VPNS.

5. Virtual Private Networks.

    Introduction

    PPTP

    L2TP

    Other VPNs

    Summary

    Exercises

6. Secure Sockets Layer.

    Introduction

    Cipher Suites

    The SSL Protocol

    SSL on the Wire

    OpenSSL

    The stunnel Program

    SSL Security

    Summary

    Exercises

7. SSH.

    Introduction

    The SSHv1 Protocol

    The SSHv2 Protocol

    Building VPNs with SSH

    Summary

    Exercises

8. Lightweight VPNs.

    Introduction

    Vtun

    CIPE

    Tinc

    OpenVPN

    Summary

    Exercises

III. IPSEC.

9. IPsec.

    Introduction

    An Overview of IPsec

    Road Map for Part 3

    Summary

    Exercises

10. IPsec Architecture.

    Introduction

    Protocols

    IPsec Modes

    Security Associations

    Combining Security Associations

    Policies

    IPsec Processing

    Summary

    Exercises

11. AH.

    Introduction

    The AH Header

    Sequence Numbers

    AH Processing

    Transport Mode

    Tunnel Mode

    AH with IPv6

    Summary

    Exercises

12. ESP.

    Introduction

    The ESP Header

    ESP Processing

    Transport Mode

    Tunnel Mode

    ESP with IPv6

    Summary

    Exercises

13. IKE.

    Introduction

    ISAKMP

    IKE

    An Example Negotiation

    Summary

    Exercises

14. IPsec Futures.

    Introduction

    IPsec Architecture

    AH

    ESP

    IKE

    NAT Traversal

    Summary

    Exercises

Appendix A: Source Code.

    Introduction

    Cryptographic Routines

    Library Code

Appendix B: Miscellaneous Software.

    Netcat

    tcpdump and Other Packet Sniffers

    ssldump

    PPP

Bibliography.

Index.