1. Configure MPLS.
2. Configure BGP.
3. Configure an IGP.
4. Configure LDP.
5. Configure VRF.
6. Enable carrier-of-carriers support on the VRF; use the mpls topology-driven-lsp
command in the context of the VRF virtual router to enable MPLS support.
7. Enable LDP on the interface in the VRF that connects to the customer carrier’s
PE router.
8. Use the show ip bgp vpnv4 vrf vrfname summary command to verify that
carrier-of-carriers support is enabled.
On the customer carrier’s PE router that connects to the provider carrier’s PE router:
1. Configure MPLS.
2. Configure BGP.
3. Configure an IGP.
4. Configure LDP—Enable carrier-of-carriers support on the VR; use the mpls
topology-driven-lsp command in the context of the VRF virtual router to enable
LDP support.
5. Enable LDP on the interface in the VR that connects to the provider carrier’s PE
router.
Customer Carrier as a VPN Service Provider
The carrier-of-carriers VPN can be used to create two-tiered hierarchical VPNs. In a
hierarchical VPN, the provider carrier’s VPN is the backbone, or tier-1 VPN, and the
customer carrier provides the tier-2 VPN services to its customers.
In a hierarchical VPN environment, each carrier maintains the internal routes of its
customers in VRF tables on its PE routers. Routes are learned and maintained as
follows:
■In the provider carrier’s VPN, PE routers use MP-IBGP to exchange labeled VPN
routes that correspond to the internal routes of the customer carrier’s VPN sites.
■In the customer carrier’s VPN, PE routers use MP-IBGP sessions to exchange
labeled VPN routes that correspond to the end customer’s VPN routes.
Figure 108 on page 473 shows a sample carrier-of-carriers environment in which the
customer carrier provides VPN services to its customers.
472 â– Carrier-of-Carriers IPv4 VPNs
JUNOSe 11.1.x BGP and MPLS Configuration Guide