MPLS and VPN Architectures, CCIP™ Edition

Chapter 9. MPLS/VPN Architecture Overview

This chapter includes the following topics:

• VPN Routing and Forwarding Tables

• Overlapping Virtual Private Networks

• Route Targets

• Propagation of VPN Routing Information in the Provider Network

• VPN Packet Forwarding

In the previous chapter, you learned about Virtual Private Network (VPN) evolution; two major VPN models, overlay VPN and peer-to-peer VPN; and the major technologies used to implement both VPN models.

The overlay VPN model, most commonly used in a service provider network, dictates that the design and provisioning of virtual circuits across the backbone must be complete prior to any traffic flow. In the case of an IP network, this means that even though the underlying technology is connectionless, ...