Virtual Private Network (VPN) has become one of the most recognized terms in our industry, but there continues to appear different impressions of what VPNs really are and can become. A Technical Guide IPSec Virtual Private Networks provides a single point of information that represents hundreds or resources and years of experience with IPSec VPN solutions. It cut through the complexity surrounding IPSec and distinctive design, implementation, operation, and security.Starting with a primer on the IP protocol, book travel through layers upon layers of protocols and technologies that make VPNs possible. A Technical Guide IPSec Virtual Private Networks arms information security, network and systems engineers and administrators with the knowledge and methodologies for designing and using the VPN in the real world for real companies.