Interprovider VPN Example—Multihop MP-EBGP with P Routers

In this example, labeled IPv4 (not VPN-IPv4), routes are exchanged by the AS border routers (Router C and Router D) to provide Multiprotocol Label Switching (MPLS) connectivity between the PE routers. Router G and H are provider routers.

Figure 52 illustrates the network topology used in this VPN example.

Figure 52: Network Topology of Interprovider VPN Example—Multihop MP-EBGP

Only routes internal to the service provider networks should be announced between Router C and Router D. Configure this by including the family inet labeled-unicast statement in the IBGP and EBGP configuration on the PE routers. When you set family inet labeled-unicast, the local router announces internal routes from inet.0 in the following manner:

• If a label exists for the route, the local router creates a label, performs a swap, and announces the route from inet.0 with the label.
• If a label does not exist for the route, the local router creates a label, performs a pop, and announces the route from inet.0 with the label.

Routes learned from the labeled-unicast session are placed into the inet.0 routing table.

In addition, you configure a multihop MP-EBGP session between the end PE routers (Router B and Router E). This additional MP-EBGP session allows the announcement of VPN-IPv4 routes, and allows you to maintain VPN connectivity while keeping VPN-IPv4 routes out of the core of the network.

For configuration information, see the following sections:

• Configuration for Router A
• Configuration for Router B
• Configuration for Router C
• Configuration for Router D
• Configuration for Router E
• Configuration for Router F

Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice.