A lookup unit matrix combines a plurality of lookup units to provide a
longest prefix match for a search key longer than the lookup unit's mapper
key. A portion of the search key is provided to each of the plurality of
lookup units in a single search request issued to the lookup unit matrix.
Each lookup unit in the lookup unit matrix performs a multi-level search
for the result value based on the portion of the search key forwarded as
the mapper key and the result of a multilevel search in the previous
lookup unit. The search results in a value corresponding to the search key
stored in a single location in one of the lookup units.
