IP Lookup in IPv6 Networks

The IP Lookup Process is a key bottleneck in routing because of increasing routing table sizes, increasing traffic, higher speed links, and migration to 128-bit IPv6 addresses. The IP routing lookup involves computation of the best matching prefix (BMP) for which existing solutions, such as BSD Radix Tries, scale poorly when traffic in the router increases or when employed for IPv6 address lookups. In this paper a distributed memory organization technique for the routing table was described, which performs extremely well for IPv6 address lookup. This mechanism provides lookup for a maximum of 16 IPv6 addresses simultaneously. In each lookup subsystem, a scheme for BMP using binary search on hash tables organized by prefix length was proposed. An optimized storage mechanism for binary search on hash table scheme is also presented. Using the proposed techniques a router can achieve a much higher packet forwarding rate and throughput. Keywords— IP lookup, IPv6, Distributed Memory Organization, Binary search, Hash table.