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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_inter
val 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_inte
rval 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).
Intermediate System to Intermediate System (IS-IS) 719