A network, comprising: a core network, including a plurality of core packet switching devices, with each of the plurality of core packet switching devices configured to perform operations; and a plurality of edge packet switching devices, with each of the plurality of edge packet switching devices configured to perform operations, including communicating packets with the core network, and with one or more external networks or devices; wherein said configuration of each of the plurality of core packet switching devices and said configuration of each of the plurality of edge packet switching devices includes exchanging Internet Protocol, IP, routing information in a manner to distribute said IP routing information among the plurality of core packet switching devices and the plurality of edge packet switching devices; and wherein said configuration of each particular core packet switching device of the plurality of core packet switching devices includes: maintaining said IP routing information; filtering said IP routing information to produce a fewer number, than in said IP routing information, of IP routes that are installed in one or more forwarding information bases, FIBs, within the particular core packet switching device, wherein said installed IP routes include a plurality of IP routes respectively corresponding to each of the plurality of core packet switching devices and each of the plurality of edge devices; and forwarding packets, based on said one or more FIBs within the particular core packet switching device, to other packet switching devices of the plurality of core packet switching devices and the plurality of edge packet switching devices, wherein said one or more FIBs, in each particular core packet switching device includes an exact match FIB and a longest prefix matching FIB; and wherein said configuration of each of the plurality of core packet switching devices includes: installing, in the exact match FIB, routes within the network; and installing, in the longest prefix matching FIB, routes that are external to the network. a core network, including a plurality of core packet switching devices, with each of the plurality of core packet switching devices configured to perform operations; and a plurality of edge packet switching devices, with each of the plurality of edge packet switching devices configured to perform operations, including communicating packets with the core network, and with one or more external networks or devices; wherein said configuration of each of the plurality of core packet switching devices and said configuration of each of the plurality of edge packet switching devices includes exchanging Internet Protocol, IP, routing information in a manner to distribute said IP routing information among the plurality of core packet switching devices and the plurality of edge packet switching devices; and wherein said configuration of each particular core packet switching device of the plurality of core packet switching devices includes: maintaining said IP routing information; filtering said IP routing information to produce a fewer number, than in said IP routing information, of IP routes that are installed in one or more forwarding information bases, FIBs, within the particular core packet switching device, wherein said installed IP routes include a plurality of IP routes respectively corresponding to each of the plurality of core packet switching devices and each of the plurality of edge devices; and forwarding packets, based on said one or more FIBs within the particular core packet switching device, to other packet switching devices of the plurality of core packet switching devices and the plurality of edge packet switching devices, maintaining said IP routing information; filtering said IP routing information to produce a fewer number, than in said IP routing information, of IP routes that are installed in one or more forwarding information bases, FIBs, within the particular core packet switching device, wherein said installed IP routes include a plurality of IP routes respectively corresponding to each of the plurality of core packet switching devices and each of the plurality of edge devices; and forwarding packets, based on said one or more FIBs within the particular core packet switching device, to other packet switching devices of the plurality of core packet switching devices and the plurality of edge packet switching devices, wherein said one or more FIBs, in each particular core packet switching device includes an exact match FIB and a longest prefix matching FIB; and wherein said configuration of each of the plurality of core packet switching devices includes: installing, in the exact match FIB, routes within the network; and installing, in the longest prefix matching FIB, routes that are external to the network. installing, in the exact match FIB, routes within the network; and installing, in the longest prefix matching FIB, routes that are external to the network.