Defined by IETF RFC-2547bis and RFC-4364, Layer 3 VPNs (L3VPNs) use extensions to the existing Internet routing protocol BGPv4 to interconnect remote customer sites through an MPLS network. L3VPN is a virtual private routed network solution for IP data traffic only.

Central to an L3VPN is the VPN routing and forwarding (VRF) table, which allows for separate and private VPN forwarding decisions to co-exist within a PE device. The VRF is the fundamental mechanism that enables the partitioning of individual customers over the shared IP routed infrastructure.

MPLS Manager requires a Level 3 VPN feature license for the discovery of L3VPNs.