1. A processor-implemented method for generating a plurality of hash values for an input key, the method comprising: (a) hashing the input key using a set of seed hash functions to generate a set of seed hash values for the input key, wherein the input key is a candidate prefix value for a given network address; (b) combining two or more of the seed hash values one or more different ways to generate one or more additional hash values for the input key; and (c) using the seed hash values and one or more additional hash values to perform membership probes into a Bloom filter programmed with prefix values of a routing table having a plurality of different prefix lengths.