Fast flexible search engine for longest prefix match

摘要

A subprefix is selected from a prefix search tree that has a longest match to a search prefix. A binary search prefix is input to the root vertex of the tree, and is compared to the prefixes in selected hierarchy vertices. A bit is set in a search mask based on a least significant bit of a bit string in the search prefix that matches a longest bit string in a prefix in each vertex. A longest matching subprefix is selected from a string of most significant bits of the search prefix based on the lowest significant bit set in the search mask. A prefix mask is also provided for each prefix in the tree, and is useful in connection with construction of the search mask.