When designing a single-customer full‑mesh MPLS L3 VPN, what requirement applies to route targets (RTs) within that VPN?

For a single-customer full-mesh MPLS L3 VPN, all Provider Edge (PE) routers participating in that VPN must use the same Route Target (RT) values for both importing and exporting routes. This ensures that all VPN routes are exchanged among all PEs, creating the full-mesh topology. If RTs were different, routes might not be imported by all PEs, breaking the full-mesh connectivity. An RT does not need to be identical to a Route Distinguisher (RD) value; RDs differentiate prefixes within the VPN routing and forwarding (VRF) table, while RTs control route exchange between VRFs. RTs also don't need to be globally unique across all VPNs, only consistently applied within a specific VPN to achieve the desired topology.