Architectural Overview of MPLS VPN
To achieve MPLS VPN, you need some basic building blocks on the PE routers. These building blocks are the following: VRF, route distinguisher (RD), route targets (RT), route propagation through MP-BGP, and forwarding of labeled packets.
Virtual Routing Forwarding
A virtual routing/forwarding (VRF) is a VPN routing and forwarding instance. It is the name for the combination of the VPN routing table, the VRF Cisco Express Forwarding (CEF) table, and the associated IP routing protocols on the PE router. A PE router has a VRF instance for each attached VPN. Look at Figure 7-3 to see that a PE router holds the global IP routing table, but also a VRF routing table per VPN connected to the PE.
Figure 7-3. VRFs on ...
Get MPLS Fundamentals now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
