1. A method, comprising: populating, based on one or more user-configurable control-plane parameters by a control plane of a particular packet switching appliance in a network from a forwarding information base (FIB) of the particular packet switching appliance, FIB entries into a plurality of different groups of FIB entries defined by said one or more user-configurable control-plane parameters; and data plane-processing, by the particular packet switching appliance, of a plurality of packets based on said populated FIB entries; wherein said user-configurable control-plane parameters include defining selective implementation of providing or not providing equal-cost multi-path (ECMP) forwarding for the plurality of different groups of FIB entries, with said user-configurable control-plane parameters specifying at least one of the plurality of different groups of FIB entries to support ECMP forwarding, and with the method including associating one or more ECMP entries with one or more FIB entries in said at least one of said plurality of different groups of FIB entries.