timer lsp-generation (IS-IS view)

Function

The timer lsp-generation command sets an LSP generation interval for a specified IS-IS process.

The undo timer lsp-generation command restores the default configuration.

By default, the LSP generation interval is 2 seconds.

Format

timer lsp-generation max-interval [ init-interval [ incr-interval ] ] [ level-1 | level-2 ]

undo timer lsp-generation [ max-interval [ init-interval [ incr-interval ] ] ] [ level-1 | level-2 ]

Parameters

Parameter	Description	Value
max-interval	Specifies a maximum LSP generation interval.	The value ranges from 1 to 120 seconds. The default value is 2 seconds.
init-interval	Specifies an initial LSP generation interval.	The value is an integer ranging from 1 to 60000, in milliseconds. By default, this interval is not used.
incr-interval	Specifies an incremental LSP generation interval.	The value is an integer ranging from 1 to 60000, in milliseconds. By default, this interval is not used.
level-1	Applies the interval setting to Level-1 LSPs.	-
level-2	Applies the interval setting to Level-2 LSPs. If neither Level-1 nor Level-2 is specified, the interval setting applies both to Level-1 and Level-2 LSPs.	-

Views

IS-IS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

For IS-IS, when the local routing information is changed, some new LSPs (or LSP fragments) need to be generated to advertise the change of routes. If the change occurs frequently, immediate generation of LSPs (or LSP fragments) will consume a large number of resources.

To speed up network convergence and prevent the system from being affected, use an intelligent timer to control the LSP generation interval. Using the timer, you can adjust the LSP generation interval based on the route change frequency.

Before using the

timer lsp-generation command, note the following:

When only max-interval is specified, the intelligent timer functions as a one-shot timer.
If init-interval and incr-interval are specified, init-interval is used as the LSP generation interval for the first time, and incr-interval is used as the LSP generation interval for the second time. From the third time on, the LSP generation interval doubles each time until the interval reaches max-interval. If the local routing information keeps being updated within the max-interval period, the interval remains at max-interval until the time the local routing information is not updated within the max-interval period or the IS-IS process is restarted. Then the interval decreases to init-interval.
If init-interval is specified, but incr-interval is not, init-interval is used as the LSP generation interval for the first time, and then max-interval is used as the interval. If the local routing information keeps being updated within the max-interval period, the interval remains at max-interval until the time the local routing information is not updated within the max-interval period or the IS-IS process is restarted. Then the interval decreases to init-interval.

Prerequisites

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

Configuration Impact

If the LSP generation interval is too long, the device cannot advertise its changes to neighbors in time, which slows down network convergence.

Precautions

When the network topology changes for the first time, the device immediately generates LSPs to notify the changes and then starts the intelligent timer.

Example

# Set the LSP generation interval to 5s.

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

# Set the maximum LSP generation interval to 20s, initial interval to 50 ms, and incremental interval to 2000 ms.

<HUAWEI> system-view
[~HUAWEI] isis
[*HUAWEI-isis-1] timer lsp-generation 20 50 2000