Network routing apparatus employs multi-level tree data structures in a centralized routing table (144, 146, 148) and in distributed forwarding tables (150, 152, 154, 158, 160). Each level of each structure is associated with a different field of a network address appearing in received packets. Pointers in each structure are used to identify either an address of a next hop network, or a next-level tree to be examined for a next-hop address. An uncompressed tree routing table uses directly addressed trees in order to simplify the storage and retrieval of pointers, and the next-tree pointers directly identify next trees. Compressed tree forwarding tables are generated from the uncompressed routing table by reducing the number of pointers stored at one or more levels to substantially the number of unique next hop addresses associated with network addresses at that level. A single mapping table maps pointer values at one level to the locations of trees at the next level in the compressed trees. Next hop address lookup logic (50, 52, 76, 78) performs lookups in accordance with the structure of the compressed trees. Also, the lookup logic stores and selectively operates on multiple forwarding tables in order to provide support for virtual router operation.

Appareil de recherche dacheminement de reseau utilisant une table dacheminement arborescente comprimee
Network router search engine using compressed tree forwarding table
Publication Number
Application Date
February 23, 2000
Publication Date
August 31, 2000
Heyda Russell L
Lipman Michael E
Juniper Networks
Redstone Communications
H04L 12/56
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