Installing and using a subset of routes for forwarding packets

A particular packet switching device, comprising:

• one or more processing elements;
• memory;
• a plurality of interfaces configured to send and receive packets;
• and
• one or more packet switching mechanisms configured to packet switch packets among said interfaces;
• wherein said one or more processing elements are configured to perform operations, including:
• exchanging Internet Protocol (IP) routing information with other devices in a particular network, with the particular network including a plurality of other core packet switching devices and a plurality of edge packet switching devices;
• maintaining said IP routing information;
• filtering said IP routing information to produce a significantly fewer number of IP routes than the number IP routes in said IP routing information and installing said significantly fewer number of IP routes in one or more forwarding information bases (FIBs) within the particular 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 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 an IP route is an IP address that is a fully or partially expanded prefix, not a path.

A method, comprising:

• performing operations by a particular packet switching device, with said operations comprising:
• exchanging Internet Protocol (IP) routing information with other devices in a particular network, with the particular network including a plurality of other core packet switching devices and a plurality of edge packet switching devices;
• maintaining said IP routing information;
• filtering said IP routing information to produce a significantly fewer number of IP routes than the number IP routes in said IP routing information and installing said significantly fewer number of IP routes in one one or more forwarding information bases (FIBs) within the particular 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 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 an IP route is an IP address that is a fully or partially expanded prefix, not a path.