Reference Guide

for all practical purposes of routing, the interface is deemed to be “down.” After the interface becomes stable and the
penalty decays below a certain threshold, the interface comes up again and the routing protocols re-converge.
Link dampening:
• reduces processing on the CPUs by reducing excessive interface flapping.
• improves network stability by penalizing misbehaving interfaces and redirecting traffic.
• improves convergence times and stability throughout the network by isolating failures so that disturbances are
not propagated.
Important Points to Remember
• Link dampening is not supported on VLAN interfaces.
• Link dampening is disabled when the interface is configured for port monitoring.
• You can apply link dampening to Layer 2 and Layer 3 interfaces.
• You can configure link dampening on individual interfaces in a LAG.
Enabling Link Dampening
To enable link dampening, use the following command.
• Enable link dampening.
INTERFACE mode
dampening
R1(conf-if-gi-1/1)#show config
!
interface GigabitEthernet 1/1
ip address 10.10.19.1/24
dampening 1 2 3 4
no shutdown
R1(conf-if-gi-1/1)#exit
To view the link dampening configuration on an interface, use the show config command. To view dampening
information on all or specific dampened interfaces, use the
show interfaces dampening command from EXEC
Privilege mode.
Example of the show interfaces dampening Command
FTOS# show interfaces dampening
InterfaceStateFlapsPenaltyHalf-LifeReuseSuppressMax-Sup
Gi 0/0Up005750250020
Gi 0/1Up21200205001500300
Gi 0/2Down4850306002000120
To view a dampening summary for the entire system, use the show interfaces dampening summary
command from EXEC Privilege mode.
Example of the show interfaces dampening summary Command
FTOS# show interfaces dampening summary
20 interfaces are configured with dampening. 3 interfaces are currently
suppressed.
Following interfaces are currently suppressed:
Gi 0/2
Gi 3/1
Gi 4/2
FTOS#
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