Method for avoiding neighbourhood oscillation of intermediate system and an intermediate system

Abstract

The invention discloses a method for avoiding neighborhood flap in an intermediate system (IS). When updating the state information of N links in the link state data base (LSDB) of an IS, the IS does not send a neighboring IS a partial sequence number packet (PSNP) carrying the summary information of the N link state packets (LSPs) one-to-one corresponding to the state information of the N links instead of the N LSPs, so that the neighboring IS can update the LSDB thereof according to the summary information of the N LSPs; wherein N is natural numbers. The invention also discloses an IS. The technical proposal provided in the invention remarkably reduces ISIS packet when updating the LSPs, so as to avoid ISIS neighborhood flap due to fullness of ISIS packet sending and receiving queues.

Description

technical field [0001] The invention relates to the technical field of network communication, in particular to a method for avoiding the oscillation of neighbor relations in an intermediate system and an intermediate system. Background technique [0002] Intermediate System-to-Intermediate System intra-domain routing information exchange protocol (Intermediate System-to-Intermediate System intra-domain routing information exchange protocol), referred to as ISIS protocol was originally a dynamic routing protocol designed by the International Organization for Standardization (ISO) for its connectionless network protocol . In order to provide routing support for IP, the Internet Engineering Task Force (IETF) extended and modified the ISIS protocol in RFC1195, so that it can be applied in both TCP / IP and OSI environments, called Integrated ISIS (Integrated ISIS or Dual ISIS). The ISIS protocol is a link-state protocol that uses the Shortest Path First (SPF) algorithm for routi...

AI Technical Summary

Problems solved by technology

[0016] 1. If the link state information in the LSDB of MRT1 is periodically updated, the sending queue of ISIS packets of MRT1 may be full, so that some Hello packets cannot be sent out or cannot be sent on time, causing neighbors such as RT1 and MRT1’s neighbors to When the relationship times out, the neighbor relationship fluctuates, and the neighbor relationship flapping will cause routers such as MRT1 and RT1 to regenerate LSPs, causing MRT1 to send more ISIS packets, resulting in a vicious circle, causing the ISIS neighbor relationship to constantly fluctuate;

[0017]2. If the link state information in the LSDB of routers RT1 and RT2 is periodically updated, it may cause the ISIS message receiving queue of MRT1 to be full, so that RT1 MRT1 may discard the Hello packets sent by routers such as RT1 and RT2, and MRT1 will consider that the neighbor relationship between RT1 and RT2 has timed out.

This method requires all routers to support BFD, and RT1, RT2 to RTN are low-end routers usually do not support BFD function, and the links between RT1, RT2 to RTN and MRT1 and MRT2 are usually low-speed links, run BFD requires a large amount of bandwidth; MRT1 and MRT2 need to establish a large number of ISIS neighbors, and then need to establish the same number of BFD connections, which may exceed the BFD specification limit

[0022] To sum up, when an IS establishes an ISIS neighbor relationship with multiple ISs, due to the periodic update of the link state information in the LSDB, it may cause The burst of LSPs causes the receiving and sending queues of ISIS packets to overflow, causing the relationship between ISIS neighbors to fluctuate.

But there is not yet an effective solution to this problem in the prior art

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