An evaluation of IP-address lookup algorithms

Due to the manyfold increase in Internet traffic, backbone links and routers of multigigabit capacity are commonly deployed. One of the major bottlenecks in the optimum performance of such high-speed routers is address lookup while performing longest prefix match. The problem is further compounded by the introduction of 128 bit addresses in IPv6 technology. Due to the importance of the address lookup problem several algorithms have been proposed in recent years. This paper presents an evaluation of state-of-art IP address lookup algorithms. Both software and hardware based algorithms are discussed in terms of space/time complexity, lookup speed, scalability and update overheads.