Chapter 13. Virtual Private Networks

The demand for VPNs is growing each day. VPNs today give customers many different options for connectivity between multiple sites across a shared infrastructure. Today's VPNs also serve to provide more reliable, scalable, and cost-effective ways for service providers to offer services to customers, utilizing their existing IP infrastructures . This chapter describes the different design models and network topologies used when implementing VPNs. In addition, it will cover some of the different VPN applications and business cases for their use. After allowing the reader to become familiar with this technology, case studies will be used to shift gears and focus primarily on the implementation and configuration of BGP/MPLS VPNs. This is the RFC 2547bis implementation of Layer 3 VPNs that is supported by the Juniper Networks routers.