Method for stable restart of router realizing fast route convergence

Abstract

Before being restarted smoothly, router generates an Opaque LSA 'flooding' in own domain to inform other router that self is ready to restart smoothly. After receiving the Opaque LSA, remote routers mark links relevant to the smooth restarted router as status indication of 'potential unavailable', but no operation is executed. Till receiving Opaque LSA indicating that smooth restarting state is ended from the router, remote routers deletes the said status indication. But, if in restarting, synchronizing or ending phases, change of link status happens in network, then remote routers will switches status indications of links relevant to the smooth restarted router from 'potential unavailable' to 'unavailable' as well as updates information base of link status and recalculates routes immediately, and remote routers makes the said corresponding action unnecessary waiting for a unavailable LSA of relevant links sent from router adjacent to the smooth restarting router.

Description

technical field [0001] The invention relates to a method for stably restarting a router for realizing rapid route convergence, and belongs to the technical field of data communication. Background technique [0002] When the link state changes, the convergence time of the traditional routing protocol on the IP network is generally more than ten seconds. During the convergence period, routing loops and black holes will occur, resulting in incorrect delivery of data packets. With the development of technology, IP networks are carrying more and more real-time services such as voice and video. These services are obviously different from the previous services such as e-mail and web browsing. The quality of service (QoS) requirements and the tolerable service interruption time It is usually expected to be within 1 to 2 seconds, so the convergence time of the IP network must be accelerated. The ways to achieve fast routing convergence mainly include: shortening the fault detection ...

AI Technical Summary

Problems solved by technology

[0014] However, the result of this processing is that other routers in the network will receive two consecutive link state updates in a short period of time. Take the restart of router A as an example: because the adjacent router Y only generates LSA (B-Cfail) after receiving the LSA (B-Cfail). LSA (X-Y fail), so in most cases, restarting router A will receive LSA (B-C fail) first. In the fast route convergence mechanism, the restarting router A will immediately update the link state information database and recalculate the routing table ; However, during the calculation process or just after the calculation, it will receive LSA ((X-Y fail), so that the restart router A will need to update the link state information base and recalculate the routing table

[0015] If multiple routers in the network are in the process of graceful restart at the same time, a single link status change somewhere will cause each router to receive multiple different link status messages consecutively in a short period of time. In the case of route convergence, these routers may update their link state information database and recalculate the routing table multiple times, which affects the speed of route convergence.

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