This tutorial is aimed at technical folks who want to understand the overall workings of a virtual private network or VPN. It is a survey of the VPN field, not an in-depth analysis. However, knowledge of basic networking concepts is recommended.

Part 1 starts with a high-level VPN overview, proceeds to the technologies involved, and delves into the IPSec protocol, while Part 2 will take a closer look at this technology and examine some VPN implementations of note.