Generally described, computing devices utilize a communication network, or a series of communication networks, to exchange data. In a common embodiment, data to be exchanged is divided into a series of packets that can be transmitted between a sending computing device and a recipient computing device. In general, each packet can be considered to include two primary components, namely, control information and payload data. The control information corresponds to information utilized by one or more communication networks to deliver the payload data. For example, control information can include source and destination network addresses, error detection codes, and packet sequencing identification, and the like. Typically, control information is found in packet headers and trailers included within the packet and adjacent to the payload data.
In practice, in a packet-switched communication network, packets are transmitted between multiple physical networks, or sub-networks. Generally, the physical networks include a number of hardware devices that receive packets from a source network component and forward the packet to a recipient network component. The packet routing hardware devices are typically referred to as routers. Generally described, routers can operate with two primary functions or planes. The first function corresponds to a control plane, in which the router learns the set of outgoing interfaces that are most appropriate for forwarding received packets to specific destinations. The second function is a forwarding plane, in which the router sends the received packet to an outbound interface.
To execute the control plane functionality, routers can maintain a forwarding information base (“FIB”) that identifies, among other packet attribute information, destination information for at least a subset of possible network addresses, such as Internet Protocol (“IP”) addresses. In a typical embodiment, the FIB corresponds to a table of values specifying network forwarding information for the router. In one aspect, commercial level routing hardware components can include customized chipsets, memory components, and software that allows a single router to support millions of entries in the FIB. However, such commercial level routing hardware components are typically very expensive and often require extensive customization. In another aspect, commodity-based routing hardware components are made of more generic components and can be less expensive than commercial level routing hardware components by a significant order of magnitude. However, such commodity-based routing hardware components typically only support FIBs on the order of thousands of entries.