Routing table construction method and device and routing table lookup method and device

Abstract

The embodiments of the present invention relate to a routing table establishment method and device and a routing table lookup method and device. The routing table establishment method includes: partitioning a data structure of a routing table into a trunk and a TRIE sub-tree (101); adding entries of the routing table to the TRIE sub-tree (102); and storing an upgrade sub-node of the TRIE sub-tree's root in the trunk, where the height of the TRIE sub-tree is smaller than or equal to a set height threshold (103), and the upgrade sub-node of the TRIE sub-tree's root is a sub-root among prefix sub-nodes included in the TRIE sub-tree's root. According to the embodiments of the present invention, the data structure of the routing table is partitioned into the trunk and the TRIE sub-tree, and the TRIE sub-tree is established by using the TRIE algorithm, thereby ensuring the high compression ratio of the routing table; and the height of the TRIE sub-tree is controlled according to the height threshold, thereby reducing times for accessing a memory, improving lookup speed, and reducing lookup delay.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of communication, and in particular to a method and device for establishing a routing table and a method and device for searching a routing table. Background technique [0002] In order to prevent the address space from being exhausted, the Internet Engineering Task Force (IETF for short) proposed a temporary solution to the address structure of Classless Inter-Domain Routing (CIDR for short) in 1993. CIDR is the basis of the actual routing lookup table, which breaks away from the traditional A-E classification address structure. In CIDR, an IP network is represented by a prefix (prefix), which is represented by a composite of an IP address and a mask identifying the valid bits of the IP address. CIDR allows routers to perform route aggregation, that is, routing table entries of 2 subnets with the same size, adjacent to each other in the address space, and the same route can be com...

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