Which Layer 3 VPN attribute allows different customers to use the same MPLS core with overlapping IP ranges?

The Route Distinguisher (RD) is a 64-bit value prefixed to an IPv4 address, creating a unique 96-bit VPNv4 address. This ensures that routes from different customers, even if they use the same IP ranges, are distinct within the MPLS backbone. Without the RD, the MPLS core would see duplicate routes and be unable to differentiate between customers. Route Target (RT) is used for controlling the import and export of routes between VRFs, defining which routes are shared. VRF (Virtual Routing and Forwarding) is a virtual routing table that isolates customer traffic on a router but doesn't solve the overlapping IP issue across the core itself. MP-BGP (Multiprotocol BGP) is the routing protocol used to exchange VPNv4 routes but relies on the RD to make those routes unique.