Handbook of Information Security: Threats, Vulnerabilities, Prevention, Detection, and Management, Volume 3

VPN Basics

G. I. Papadimitriou, Aristotle University

M. S. Obaidat, Monmouth University

C. Papazoglou and A.S. Pomportsis, Aristotle University

Introduction

Types of VPN Services

Intranet VPNs

Extranet VPNs

Remote Access VPNs

Tunneling

Security Concerns

Cryptography

Integrity Checksums

Authentication

Access Management

VPN Implementations

Hardware Components

Protocols Employed by VPNs

Point-to-Point Tunneling Protocol

Layer-2 Tunneling Protocol (L2TP)

IP Security

SOCKS v5 and SSL

Multiprotocol Label Switching

Quality of Service Support

Conclusions

Glossary

Cross References

References

Further Reading

INTRODUCTION

The best way to come up with a definition of the term virtual private network (VPN) is to analyze each word separately. Having done that, Ferguson and Huston (1998) came up with the following definition: A VPN is a communications environment in which access is controlled to permit peer connections only within a defined community of interest and is constructed through some form of partitioning of a common underlying communications medium, where this underlying communications medium provides services to the network on a nonexclusive basis. Ferguson and Huston also provided a simpler and less formal description. A VPN is a private network constructed within a public network infrastructure, such as the global Internet. Others define a VPN as a network that allows two or more private networks to be connected over a publicly accessed network. It is similar to wide area networks ...