Reference Guide

418 | Interfaces
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dampening
s z
Configure dampening on an interface.
Syntax
dampening [[[[half-life] [reuse-threshold]] [suppress-threshold]] [max-suppress-time]]
To disable dampening, use the no dampening [[[[half-life] [reuse-threshold]]
[suppress-threshold]] [max-suppress-time]] command syntax.
Parameters
Defaults
Disabled
Command Modes
INTERFACE (conf-if-)
Command History
Example
FTOS(conf-if-gi-3/2)#dampening 20 800 4500 120
FTOS(conf-if-gi-3/2)#
Usage Information
With each flap, FTOS penalizes the interface by assigning a penalty (1024) that decays exponentially
depending on the configured half-life. Once the accumulated penalty exceeds the suppress threshold
value, the interface is moved to the error-disabled state. This interface state is deemed as “down” by all
static/dynamic Layer 2 and Layer 3 protocols. The penalty is exponentially decayed based on the
half-life timer. Once the penalty decays below the reuse threshold, the interface is enabled. The
configured parameters should follow:
• suppress-threshold should be greater than reuse-threshold
• max-suppress-time should be at least 4 times half-life
S6000
half-life
Enter the number of seconds after which the penalty is decreased. The
penalty is decreased by half after the half-life period expires.
Range: 1 to 30 seconds
Default: 5 seconds
reuse-threshold
Enter a number as the reuse threshold, the penalty value below which the
interface state is changed to “up”.
Range: 1 to 20000
Default: 750
suppress-threshold
Enter a number as the suppress threshold, the penalty value above which the
interface state is changed to “error disabled”.
Range: 1 to 20000
Default: 2500
max-suppress-time
Enter the maximum number for which a route can be suppressed. The default
is four times the half-life value.
Range: 1 to 86400
Default: 20 seconds
Version 9.0.2.0 Introduced on then S6000.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.2.1.0 Introduced on the S4810
Note: Dampening cannot be applied on an interface that is monitoring traffic for other
interfaces.