Carrier-of-Carrier VPNs | Junos OS (2024)

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 (orswitches), and a functioning MPLS path is required between these routersif they exchange VPN-IPv4 routes.

For configuration information see the following sections:

Network Topology for Carrier-of-Carriers Service
Configuration for Router A
Configuration for Router B
Configuration for Router C
Configuration for Router D
Configuration for Router E
Configuration for Router F
Configuration for Router G
Configuration for Router H
Configuration for Router I
Configuration for Router J
Configuration for Router K
Configuration for Router L

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 multiplelocations.

Figure 3 shows the network topologyin this carrier-of-carriers example.

Figure 3: Carrier-of-Carriers VPN Example NetworkTopology

Configuration for Router A

In this example, Router A acts as the CE router for the endcustomer. Configure a default family inet BGP session onRouter 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 IBGPsession to Router D, and configure family-inet-vpn forthe 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 localAS:

Configuration for Router D

Router D acts as the CE router for the VPN services providedby the AS10023 network. In the BGP group configuration for group int, which handles traffic to RouterB (10.255.14.179),you include the labeled-unicast statement. You also needto configure the BGP group to-isp-red to send labeled internalroutes to the PE router (Router E).

Configuration for Router E

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

Configuration for Router F

Configure Router F to swap labels for routes running throughits interfaces:

Configuration for Router G

Configure Router G:

Configuration for Router H

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

Configuration for Router I

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

Configuration for Router J

Configure Router J to swap labels for routes running throughits interfaces:

Configuration for Router K

The configuration for Router K is similar to the configurationfor 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: