A router includes a network ingress processor and a network egress processor. The network ingress processor is configured for modifying a received MPLS packet such that an internal header thereof includes a pre-configured IP flow identifier therein in place of an as-received MPLS flow identifier. Such modifying is performed in response to the network ingress processor parsing a MPLS label stack of the received MPLS packet to determine if an existing MPLS label of the label stack needs to be replaced with an Implicit Null label and in response to determining that there is no other label in the MPLS label stack. The network egress processor includes a flow selector configured for directing packets dependent upon a type of flow identifier included in an internal header thereof, for receiving the modified MPLS packet, and for replacing the internal header with a port-specific header.