随着Internet的迅猛发展,用于主干网络互联的核心路由器的接口速率已经达到了2.5Gbps～10Gbps.这一速率要求核心路由器每秒能够转发几百万乃至上千万个以上的分组.分组转发的重要一步就是查找路由表,因此快速的路由查找算法是实现高速分组转发的关键.路由查找需要实现最长前缀匹配.近年来,研究人员提出了多种路由查找算法,以提高查找性能.分析了路由查找问题及其难点,全面综述了各种查找算法,并对它们进行了详细的分析和比较,最后指出了进一步的研究方向.

With rapid development of Internet,the line speed of core router has reached 2.5Gbps and even 10Gbps beyond.This speed orders core router to be able to forward ten millions of packets per second.Route lookup is an important step of packet forwarding,so high speed IP address lookup algorithm is the key component of high speed packet forwarding.IP address lookup requires a longest matching prefix search.In the last couple of years,various algorithms for high-performance IP address lookup have been proposed.In this paper,the difficulty of route lookup is analyzed,and a survey of all kinds of lookup algorithms,which are compared indetail,is also presented.At last,some challenging open problems are identified.

国家自然科学基金资助项目(90104002);国家863高科技发展计划资助项目(863-306-ZD-07-01)