Dell PowerEdge FN I/O Module Command Line Reference Guide 9.10(0.0)

PDF

spf-interval

Specify the minimum interval between shortest path first (SPF) calculations.

Syntax

spf-interval [level-l | level-2] interval seconds [ initial_wait_interval seconds [ second_wait_interval seconds ]]

To restore default values, use the no spf-interval [level-l | level-2] interval seconds [ initial_wait_interval seconds [ second_wait_interval seconds]] command.

Parameters

level-l	(OPTIONAL) Enter the keyword `level-1` to apply the configuration to Level-1 SPF calculations.
level-2	(OPTIONAL) Enter the keyword `level-2` to apply the configuration to Level-2 SPF calculations.
interval seconds	Enter the maximum number of seconds between SPF calculations. The range is from 0 to 120 seconds. The default is 10 seconds.
initial_wait_interval seconds	(OPTIONAL) Enter the initial wait time, in seconds, before running the first SPF calculations. The range is from 0 to 120 seconds. The default is 5 seconds.
second_wait_interval seconds	(OPTIONAL) Enter the wait interval, in seconds, between the first and second SPF calculations. The range is from 0 to 120 seconds. The default is 5 seconds.

Defaults

Refer to Parameters.

Command Modes

ROUTER ISIS ( for IPv4)
CONFIGURATION-ROUTER-ISIS-ADDRESS-FAMILY-IPV6 ( for IPv6)

Supported Modes

Full–Switch

Command History

Version	Description
9.9(0.0)	Introduced on the FN IOM.
9.2(0.0)	Introduced on the MXL 10/40GbE Switch IO Module.

Usage Information

This command spf-interval in CONFIG-ROUTER-ISIS-AF-IPV6 mode is used for IPv6 Multi-Topology route computation only. If using Single Topology mode, use the spf-interval command in CONFIG-ROUTER-ISIS mode for both IPv4 and IPv6 route computations.

SPF throttling slows down the frequency at which route calculations are performed during network instability. Even though throttling route calculations slows down network convergence, not throttling can result in a network not functioning as expected. If network topology is unstable, throttling slows down the scheduling of route calculations until the topology regains its stability.

The first route calculation is controlled by the initial wait interval and the second calculation is controlled by the second wait interval. Each subsequent wait interval is twice as long as the previous one until the wait interval reaches the maximum wait time specified ( interval seconds). After the network calms down and there are no triggers for two times the maximum interval, fast behavior is restored (the initial wait time).