A Multi-stage IPv6 Routing Lookup Algorithm Based on Hash Table and Multibit Trie

Abstract

The address length of IPv6 is 128 and it has no classification addressing, which makes routing lookup processing burden of core router is heavier and the requirements are higher. As many existing algorithms cannot adapt to new requirements after expanding to IPv6, it is necessary to propose a new routing lookup algorithm based on IPv6. After thorough analysis of the IPv6 address prefix distribution regularity, this paper proposes a new scheme based on simple data structure: Hash Table and Multibit Trie (retrieval). This algorithm first classifies the prefix value and then starts its first lookup by using the first 48bits prefix of the IPv6 Address. Simulation results show that in most cases, the algorithm needs only one memory access to find the next hop routing information. This algorithm has high lookup speed and can be easily implemented with hardware.