System and method for efficiently searching a forwarding database that is split into a bounded number of sub-databases having a bounded size

Abstract

A method, apparatus, and storage medium product are provided for forming a forwarding database, and for using the formed database to more efficiently and quickly route packets of data across a computer network. The forwarding database is arranged into multiple sub-databases. Each sub-database is pointed to by a pointer within a pointer table. When performing a longest-match search of incoming addresses, a longest prefix matching algorithm can be used to find the longest match among specialized 'spear prefixes' stored in the pointer table. After the longest spear prefixes are found, the pointer table will direct the next search within a sub-database pointed to by that spear prefix. Another longest-match search can be performed for database prefixes (or simply 'prefixes') within the sub-database selected by the pointer. Only the sub-database of interest will, therefore, be searched and all other sub-databases are not accessed. Using a precursor pointer and a sub-database of optimally bounded size and number ensures power consumption be confined only to the sub-database being accessed, and that higher speed lookup operations can be achieved since only the sub-database of interest is being searched.