The present invention is directed to a sequential tester for longest prefix search engines. The tester may include a longest prefix search engine, an inputs generator for providing a nearly random flow of input commands to the longest prefix search engine and for outputting a floating rectangle which may represent a search table of the longest prefix search engine, a coding module for providing address and prefix information to the longest prefix search engine, a mapping module for providing data information to the longest prefix search engine, a super search engine for performing super search operations, and an analyzer for computing predicted outputs of the longest prefix search engine and for comparing the predicted outputs with actual outputs computed by the longest prefix search engine.