227Configuring MPLS L3VPNThe S5500-28SC-HI and S5500-52SC-HI switches do not support MPLS L3VPN.This chapter describes only MPLS L3VPN related information. For information about basic MPLSconfiguration, see "Configuring basic MPLS." For information about BGP, see Layer 3—IP RoutingConfiguration Guide.The term "router" in this document represents both routers and Layer 3 switches.OverviewMPLS L3VPN is a PE-based L3VPN technology. It uses BGP to advertise VPN routes and uses MPLS toforward VPN packets over service provider backbones.MPLS L3VPN provides flexible networking modes, excellent scalability, and convenient support for MPLSQoS and MPLS TE.MPLS L3VPN comprises the following types of devices:• Customer edge device—A CE resides on a customer network and has one or more interfacesdirectly connected to service provider networks. It can be a router, a switch, or a host. It can neither"sense" the presence of any VPN nor does it need to support MPLS.• Provider edge device—A PE resides at the edge of a service provider network and connects one ormore CEs. On an MPLS network, all VPN services are processed on the PEs.• Provider device—A P device is a core device on a service provider network. It is not directlyconnected to any CE. It has only basic MPLS forwarding capability.Figure 58 Network diagram for MPLS L3VPN modelCEs and PEs mark the boundary between the service providers and the customers.
