Traffic Management - CCIE Routing and Switching Exam Certification Guide - page 524

MPLS VPN Router Types
MPLS VPN architectures use the following four router types:
•

P router —The service provider's internal core routers. These routers do not need to
maintain VPN routes.

•

C router —The customer's internal routers. They do not connect to the provider. These
routers do not maintain VPN routes.

•

CE router —The edge routers on the customer side that connect to the service provider.
These routers do not maintain VPN routes.

•

PE router —The edge routers on the service provider side that connect with the
customer's CE routers. PE routers maintain VPN routes for the VPNs associated with the
connected interfaces.

Figure 11-4 shows a diagram of these routers in an MPLS VPN network.

MPLS VPN Routers

Figure 11-4

Service Provider

P routers

PE routers

CE routers

PE routers CE routers

C router

C routers

Enabling MPLS
To enable MPLS, Cisco Express Forwarding (CEF) must first be enabled on all routers running
MPLS. You can accomplish this with the ip cef global command.

To enable MPLS on interfaces, use the mpls ip command, which replaces the tag-switching ip
command. This command enables Cisco's proprietary tag distribution protocol (TDP). The
mpls ip command is configured on every interface of the LSR. A simple configuration of a LSR
in a MPLS network is shown in Example 11-12.