Method for eliminating residual link state protocol data unit fragments and route equipment

Abstract

The invention provides a method for eliminating residual link state protocol data unit fragments and route equipment. The method comprises the following steps: backing up the link state protocol (LSP) information generated by an active master control board to a standby main control board; determining whether the residual LSP fragments exist or not according to the LSP information generated by a new active main control board and the LSP information backed up by the original active main control board after main / standby switching; if the residual LSP fragments exist, informing the total network to eliminate the LSP fragments. By the method and route equipment provided by the invention, the residual LSP fragments on the network can be timely eliminated, thus avoiding the black hole router from being generated.

Description

technical field [0001] The invention relates to the technical field of network communication, in particular to a method and routing equipment for clearing residual link state protocol data unit fragments. Background technique [0002] Intermediate System-to-Intermediate System intra-domain routing information exchange protocol (ISIS) is a link state protocol, which belongs to the interior gateway protocol and is used inside the autonomous system. It uses the shortest Path priority (Shortest Path First, SPF) algorithm for route calculation. It uses a synchronization mechanism to ensure that the link state information on all routers in the entire network is the same, and each router uses the SPF algorithm to calculate the best route according to the synchronized link state database (Link State Database, LSDB). The synchronization of link state information is very important, it is the basis for correct calculation of routes. [0003] ISIS diffuses its link state information t...

AI Technical Summary

Problems solved by technology

[0006] However, on the broadcast link, if the network topology changes during the NSR process, or the routing information advertised in the LSP is deleted, the number of LSP fragments generated by the local system will decrease, which will cause network Out of sync on LSDB

This is because on the broadcast link, the Complete Sequence Numbers Protocol data unit (CSNP) is sent periodically, and the periodic sending of CSNP inevitably causes the delay of LSDB synchronization time, and the farther away from The LSDB synchronization time on the router of the active / standby switching device will be longer, which will affect the correctness of the routing information calculated by the ISIS system on the network, resulting in black hole routing

[0007] On a point-to-point link, although the peer or remote router immediately sends a CSNP message for confirmation after the local system sends an LSP fragment, the CSNP message may be lost, which also causes LSDB failures. Synchronization, resulting in the generation of black hole routing

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