Since I am starting out my SP studies again I figured I would do a post on basic MPLS VPNs with VRFs and just use static routes. These are some of the base fundamentals in a MPLS VPN deployment, and from here you can quickly build out and add complexities if you wish. What I will cover here is VRF, RD, LDP, and MP BGP configurations and I will start by defining and explaining the technologies.
Virtual Routing and Forwarding, or VRF for short, is a technology that allows a router to have multiple instances of a routing table at the same time. These routing tables co-exist on the router, but yet are segmented and independent of each other. An analogy would be Server virtualization. You can have a single server running VMWare, and then under that have multiple instances of Windows running independently of each other. You can configure those servers to talk to each other, or completely isolate them away and they will have no knowledge of each other.
A Route Distinguisher, or RD, is a way to identify a VPN route in an MPLS network. What this does is add an 8-byte value to an IPv4 prefix to create a VPNv4 prefix, typically referred to as an VPN-IPv4 address. Since each customer is assinged a unique RD, their addresses are guaranteed to be unique. So if you have Customer A that has a 10/8 address space and Customer B that also has a 10/8 address space, the addition of the RD brings uniqueness to each of them. A RD looks nomally looks like 1:100