基于多层混合结构的IPv6路由表查找算法

IPv6 routing table lookup algorithm based on multi-layer hybrid structure

针对现有的大多IPv6路由表查找算法采用各种优化手段提高查找性能,却使得路由更新需要重构整个路由表的问题,提出基于多层混合结构的IPv6路由表查找算法。该算法在第一层借鉴最优查找树的优点,把前缀1～16位的不同取值按其在路由表中出现的概率降序存储在线性表中,在第二、三层把前缀的17～32位和33～48位分别用二叉平衡树组织,在第四层把49～64位使用线性表组织。实验结果表明,该算法查找速度快,占用内存少,动态增量更新速度快。

Most of the existing routing lookup algorithms usually use a variety of optimization methods to improve search performance; however they need to reconstruct the entire routing table to update routing information. Concerning this, a muhi- layer hybrid structure algorithm for IPv6 routing table lookup was proposed. The first layer used the advantage of the optimal search tree for reference. The different values of prefix 1 - 16 bit were ordered by their probability of occurrence in the routing table, and were stored in the linear list. The 17 - 32 hit and 33 - 48 bit of prefix were organized respectively with the balanced binary tree. The 49 - 64 hit of prefix was organized with the linear list. The evaluation results show that the proposed scheme performs faster, occupies less memory, and supports incremental update.