Chapter 3. Enhanced IPSec Features
Chapter 2, “IPSec Overview,” described the IPSec architecture and the basic building blocks necessary to create a VPN. In this chapter, you will read about advanced IPSec features that will both improve the scalability and fault tolerance of IPSec VPNs and mitigate some of its inherent limitations. The base topology shown in Figure 3-1 will be used to explain the advanced IPSec features in this chapter.
IPSec is a peer-to-peer type of technology; IP reachability between IPSec peers is required for an IPSec session to be established between them. It is possible that IP connectivity ...