Carrier-of-Carriers VPN Example—Customer Provides VPN Service

 

In this example, the carrier customer must run some form of MPLS (Resource Reservation Protocol [RSVP] or LDP) on its network to provide VPN services to the end customer. In the example below, Router B and Router I act as PE routers (or switches), and a functioning MPLS path is required between these routers if they exchange VPN-IPv4 routes.

For configuration information see the following sections:

Network Topology for Carrier-of-Carriers Service

A carrier-of-carriers service allows an Internet service provider (ISP) to connect to a transparent outsourced backbone at multiple locations.

Figure 1 shows the network topology in this carrier-of-carriers example.

Figure 1: Carrier-of-Carriers VPN Example Network Topology
Carrier-of-Carriers VPN Example Network
Topology

Configuration for Router A

In this example, Router A acts as the CE router for the end customer. Configure a default family inet BGP session on Router A:

Configuration for Router B

Because Router B is the PE router for the end customer CE router (Router A), you need to configure a routing instance (vpna). Configure the labeled-unicast statement on the IBGP session to Router D, and configure family-inet-vpn for the IBGP session to the other side of the network with Router I:

Configuration for Router C

Configure Router C as a label-swapping router within the local AS:

Configuration for Router D

Router D acts as the CE router for the VPN services provided by the AS 10023 network. In the BGP group configuration for group int, which handles traffic to Router B (10.255.14.179), you include the labeled-unicast statement. You also need to configure the BGP group to-isp-red to send labeled internal routes to the PE router (Router E).

Configuration for Router E

Router E and Router H are PE routers. Configure a PE-router-to-PE-router BGP session to allow VPN-IPv4 routes to pass between these two PE routers. Configure the routing instance on Router E to send labeled routes to the CE router (Router D).

Configure Router E:

Configuration for Router F

Configure Router F to swap labels for routes running through its interfaces:

Configuration for Router G

Configure Router G:

Configuration for Router H

The configuration for Router H is similar to the configuration for Router E:

Configuration for Router I

Router I acts as the PE router for the end customer. The configuration that follows is similar to the configuration for Router B:

Configuration for Router J

Configure Router J to swap labels for routes running through its interfaces:

Configuration for Router K

The configuration for Router K is similar to the configuration for Router D:

Configuration for Router L

In this example, Router L is the end customer’s CE router. Configure a default family inet BGP session on Router L: