Patent ID: 7826369
Filing Date: 2010-11-02
Classification: H04L

Abstract:
1. A method performed by a packet switching device, including a plurality of line cards, for forwarding packets based on a Forwarding Information Base (FIB) for the entire packet switching device, the method comprising: redirecting a packet to a second line card of the plurality of line cards in response to performing a first FIB lookup operation for the packet in a first portion of the FIB; wherein the first portion is stored in a first line card of the plurality of line cards, with the entire FIB not being available on the first line card for FIB lookup operations; wherein the packet is received by the first line card from a device external to the packet switching device; wherein the first portion is less than all of the forwarding information in the FIB; and wherein forwarding information for forwarding the packet is not located within the first portion of the FIB; forwarding the packet to a third line card of the plurality of line cards in response to the second line card performing a second FIB lookup operation for the packet in a subset of the FIB stored in the second line card, with the result of the second FIB lookup operation identifying to forward the packet from the third line card; wherein the subset of the FIB stored in the second line card includes said forwarding information for the packet; and forwarding the packet from the third line card to an external device; wherein each of the plurality of line cards is configured for sending and receiving packets with devices external to the packet switching device; wherein each of the plurality of line cards includes at least a portion of the FIB; and wherein the FIB is derived from a routing table generated by the packet switching device as a result of communication with other packet switching devices.