Selectively populating forwarding information bases in a packet switch

摘要

In one embodiment, forwarding information bases (FIBs) are selectively populated in a packet switch. A packet switching device determines, based on one or more protocol signaling messages, a subset, which is less than all, on which FIBs a lookup operation may be performed for identifying forwarding information for a received particular packet. The packet switching device populates each of these FIBs, but not all of the FIBs of the packet switching device, with forwarding information corresponding to the particular forwarding value. Thus, FIB resources are consumed for only those FIBs which could actually be used, and not all of the FIBs, for forwarding packets in the data plane of the packet switching device, whether these packets are received on a primary or backup path.

主权项

1. A method, comprising:
determining which plurality of ingress forwarding information bases (FIBs) in a particular packet forwarding context in which a lookup operation may be performed based on a particular forwarding value in the header of a received particular packet to identify forwarding information for the received particular packet, with said determining operation being performed by a packet switching device, with said determining operation including identifying said plurality of ingress FIBs based on which particular plurality of ingress interfaces a packet with the particular forwarding value could be received based on one or more received protocol signaling messages as said plurality of ingress FIBs are used to determine forwarding infoiuiation for packets received on said particular plurality of ingress interfaces; wherein said plurality of ingress FIBs are less than all ingress forwarding information bases actively used for forwarding packets in the data plane of the particular forwarding context in the packet switching device; and populating, by the packet switching device, each of the plurality of ingress FIBs with forwarding information corresponding to the particular forwarding value, but not all said ingress forwarding information bases actively used for forwarding packets in the data plane of the particular forwarding context in the packet switching device to exclude populating one or more non-relevant FIBs with forwarding information corresponding to the particular forwarding value that would be used for forwarding packets in the particular forwarding context if corresponding packets were received for processing by said non-relevant FIBs but said determining operation determined that said corresponding packets will not be received for processing by said non-relevant FIBs.