suppress-flapping lsp-generation

Function

The suppress-flapping lsp-generation command configures a period for the system to delay generation of the same LSP during route flapping.

The suppress-flapping lsp-generation disable command restores the default configuration.

The undo suppress-flapping lsp-generation command restores the default configuration.

By default, the system delays generation of the same LSP for 10s during route flapping.

Format

suppress-flapping lsp-generation { disable | timer delay-interval [ threshold threshold-value ] }

undo suppress-flapping lsp-generation

Parameters

Parameter	Description	Value
timer delay-interval	Specifies a period for the system to delay generation of the same LSP during route flapping.	The value is an integer ranging from 1 to 600, in seconds.
threshold threshold-value	Specifies a route flapping threshold. If a route flaps for the specified number of times, LSP generation is delayed.	The value is an integer ranging from 3 to 100, in times.

Parameter

Description

Value

timer delay-interval

Specifies a period for the system to delay generation of the same LSP during route flapping.

The value is an integer ranging from 1 to 600, in seconds.

threshold threshold-value

Specifies a route flapping threshold. If a route flaps for the specified number of times, LSP generation is delayed.

The value is an integer ranging from 3 to 100, in times.

Views

IS-IS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

On an IS-IS network, when the local routing information changes, the device sends LSPs to advertise the change. If the local routing information changes frequently and new LSPs are generated immediately, a lot of system resources will be consumed. To prevent this problem, run the suppress-flapping lsp-generation command to configure a period for the router to delay generation of the same LSP during route flapping.

The flapping suppression process is as follows:

If the same LSP is generated repeatedly within 3s, IS-IS records a flapping event and increases the flapping_count by 1. If the interval at which the system generates the same LSP is greater than 10s before flapping suppression takes effect, IS-IS clears the flapping_count. If the flapping_count is greater than threshold-value, flapping suppression takes effect.
During the flapping suppression period, IS-IS does not generate the same LSP, but the flapping_count may increase during this period. After the delay-interval elapses, IS-IS exits from flapping suppression and clears the flapping_count.

Prerequisites

An IS-IS process has been created and the IS-IS view has been displayed using the isis command.

Configuration Impact

If the device delays generation of the same LSP too long, the local routing information cannot be advertised to neighbors in time, slowing down route convergence.

Example

# Configure the device to delay generation of the same LSP for 5s after a route flaps 10 times.

<HUAWEI> system-view
[~HUAWEI] isis
[*HUAWEI-isis-1] suppress-flapping lsp-generation timer 5 threshold 10