GNS3 Topology: Inter Provider MPLS VPN (Back to Back VRF Method)

Inter-Provider VPN feature allows the VPN information to be redistributed between adjacent MPLS VPN entities so that client sites belonging to customer which is dispersed across multiple service provider backbones can communicate with each other.

To maintain the continuity of VPN services across multiple service providers, there are four different options to distribute VPNv4 information across the ASBR routers:

1- Back-to-Back VRF Method
2- Multiprotocol eBGP for VPNv4
3- Multi-hop MP-eBGP between Route-Reflectors
4- Non-VPN transit provider


In this approach, ASBRs are interconnected either via a single link consisting of logical subinterfaces or via multiple physical links. VRFs are configured on the ASBRs to collect VPN client routes. Each subinterface or interface connected between the ASBRs is dedicated to a single client VRF. The single client VRF can run eBGP, RIPv2, EIGRP, OSPF, or static routing to distribute the VPN routes to its adjacent peer.

"Lobo L, Lakshman U, 2005, MPLS Configuration on Cisco IOS Software, Cisco Press"

PART 1 (enabling MPLS and PE-PE routing configuration inside SP 1)



PART 2 (enabling MPLS and PE-PE routing configuration inside SP 2)



PART 3 (Configuring VRF instances and PE-CE routing configuration)



PART 4 (Verification of VPN)