spf-schedule-interval(OSPFv3 view)

Function

The spf-schedule-interval command sets the interval for OSPFv3 to calculate routes through an intelligent SPF timer.

The undo spf-schedule-interval command restores the default setting.

By default, the intelligent timer is enabled. The maximum interval for the SPF calculation is 5000 ms, the initial interval is 50 ms, and the Holdtime interval is 200 ms.

Format

spf-schedule-interval intelligent-timer max-interval start-interval hold-interval-1

spf-schedule-interval millisecond interval2

spf-schedule-interval delay-interval hold-interval

undo spf-schedule-interval

Parameters

Parameter	Description	Value
max-interval	Specifies the maximum interval for performing the OSPFv3 SPF calculation.	The value is an integer ranging from 1 to 120000, in milliseconds. The default value is 5000.
start-interval	Specifies the initial interval for performing the OSPFv3 SPF calculation.	The value is an integer ranging from 1 to 60000, in milliseconds. The default value is 50.
hold-interval-1	Specifies the holding interval for performing the OSPFv3 SPF calculation.	The value is an integer ranging from 1 to 60000, in milliseconds. The default value is 200.
millisecond interval2	Specifies the interval for performing the OSPFv3 SPF calculation.	The value is an integer ranging from 1 to 10000, in milliseconds.
delay-interval	Specifies the interval between the route change detection and the SPF calculation.	The value is an integer ranging from 0 to 65535, in seconds. The default value is 5.
hold-interval	Specifies the holding interval between two consecutive SPF calculations.	The value is an integer ranging from 0 to 65535, in seconds. The default value is 10.
intelligent-timer	Sets the SPF calculation interval through an intelligent timer.	-

Views

OSPFv3 view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
ospf	write

Usage Guidelines

Usage Scenario

Based on the LSDB, the device that runs OSPFv3 can calculate the Shortest Path Tree (SPT) with itself as the root based on the SPF algorithm, and determine the next hop to the destination network according to the SPT. When the OSPFv3 LSDB changes, the shortest path needs to be recalculated. Frequent network changes and SPF calculation consume many system resources and affect router performance. You can configure an intelligent timer and set a proper interval for the SPF calculation to prevent excessive router memory and bandwidth resources from being consumed.

If fast route convergence is required, you can set a millisecond-level interval to speed up route calculation. In other networking environments, the default value is recommended.

Configuration Impact

The interval for the SPF calculation is as follows:

The initial interval for the SPF calculation is specified in start-interval.
The interval for the SPF calculation for the nth (n>=2) time is equal to hold-interval-1 *2(n-2).
When the interval specified in hold-interval-1 * 2(n-2) reaches the maximum interval specified in max-interval, OSPFv3 performs the SPF calculation at the maximum interval until no SPF calculation is performed within max-interval. After the maximum interval elapses, the calculation mechanism goes back to step 1.
If no flapping occurs within the interval of max-interval that starts upon the end of the previous SPF calculation, the intelligent timer exits.
If no flapping occurs in the previous interval and flapping occurs in the current interval, SPF calculation is delayed for a period of the start-interval. After the SPF calculation is complete, the current interval is used for the next SPF calculation.

Example

# Set the maximum interval for performing the SPF calculation to 10000 ms, the initial interval to 700 ms, and the hold interval to 4000 ms.

<HUAWEI> system-view
[~HUAWEI] ospfv3 1
[*HUAWEI-ospfv3-1] spf-schedule-interval intelligent-timer 10000 700 4000

# Set the interval at which OSPFv3 route calculation is performed to 5s and the hold interval at which OSPFv3 route calculation is performed to 6s.

<HUAWEI> system-view
[~HUAWEI] ospfv3 1
[*HUAWEI-ospfv3-1] spf-schedule-interval 5 6