Chapter 7. VPN IPv6 Architecture and Services

"VPN is a generic term that covers the use of public or private networks to create groups of users that are separated from other network users and that may communicate among them as if they were on a private network" (RFC 4026). IP-based VPNs have become popular in the recent years, and, as reviewed in Chapter 1, "The Case for IPv6An Updated Perspective," the same reasons for deploying IPv4 VPNs apply to IPv6.

The "Virtual Private Network Overview" section introduces VPN terminology, the taxonomy of the various types of VPNs, and their applicability to IPv6.

IP-based VPNs can be offered as a service by a service provider (SP) or they can be deployed by the SP's customer itself. Each solution has its benefits and drawbacks.

The "Using IPsec to Implement CE-Based VPNs" section focuses on customer edge (CE)-based VPNs using IPsec, where the provider edge (PE) devices do not know anything about the routing or the addressing of the customer networks.

PE-based VPNs are explored in more detail in the "BGP-MPLS IPv6 VPNs: A PE-Based VPN Solution" section, with a focus on Multiprotocol Label Switching (MPLS) solutions.

The section "Topology Examples" contains examples of various VPN topologies discussed in this chapter.