As the demand for high bandwidth on the Internet increases, it is required to build next generation routers with the capability of forwarding multiple millions of packets per second. Reducing the required memory size of the forwarding table is a possible solution since small forward table can be integrated into the application specific integrated circuit (ASIC). In this paper a hash technique is developed to make the IP forwarding table as small as possible. The experiments show that the required memory size of the proposed scheme is smaller than other existing schemes for a large routing table. Keywords--Hash table, IP lookup, and binary trie.