O'Reilly have a reputation for high quality technical books and this is no exception. The authors run an ISP and outsourcing company so the background to the book is real commercial experience in a competitive market and they exhibit this in the book with liberal examples of real installations.

The book starts by explaining what a Virtual Private Network (VPN) is and why you need one. It then describes the technology involved including plenty of information on security and encryption, explaining the many reasons why someone would try to break into your network and how you should defend yourself from such attacks.

Chapters 3&4 cover typical Wide Area Network (WAN) and Remote Access scenarios and compare the VPN alternative, covering equipment, administration and upgrade issues. Most network administrators will be able to relate their own network configuration and requirements to the configurations presented here.

From Chapter 5 the book covers in much detail the VPN network protocols including many screen shots and diagrams for step-by-step configuration, albeit mostly based on Windows systems. I would have preferred to see a less Windows-centric view as although Windows is prevalent on the desktop, this is not the case in the core of the network where the gateways, firewalls and servers implementing the VPN are situated.

A small appendix covers emerging Internet technologies, although recent developments in Internet connectivity such as xDSL, Cable Modems and wireless technology are conspicuous by their absence. In common with many technical books the material is US-centric, although data comms is fairly standard throughout the world, the telecommunications infrastructure is not and readers outside North America will need to do their own research into the data bandwidths and pricing models for their local Telcos. Recommended.