Service Manual

Consider an interface periodically flaps as shown above. Every time the interface goes down, a penalty (1024) is added. In the
above example, during the first interface flap (flap 1), the penalty is added to 1024. And, the accumulated penalty will
exponentially decay based on the set half-life, which is set as 10 seconds in the above example. During the second interface flap
(flap 2), again the penalty (1024) is accumulated. When the accumulated penalty exceeds the configured suppress threshold
(2400), the interface state is set to Error-Disabled state. After the flap (flap 3), the interface flap stops. Then, the accumulated
penalty decays exponentially and when it reaches below the set reuse threshold (300), the interface is unsuppressed and the
interface state changes to “up” state.
Enabling Link Dampening
To enable link dampening, use the following command.
● Enable link dampening.
INTERFACE mode
dampening
To view the link dampening configuration on an interface, use the show config command.
R1(conf-if-te-1/1/1/1/1)#show config
!
interface TenGigabitEthernet 1/1/1/1
ip address 10.10.19.1/24
dampening 1 2 3 4
no shutdown
To view dampening information on all or specific dampened interfaces, use the show interfaces dampening command
from EXEC Privilege mode.
DellEMC#show interfaces dampening
Interface Supp Flaps Penalty Half-Life Reuse Suppress Max-Sup
State
Te 1/1/1/1 Up 0 0 1 2 3 4
Te 1/1/1/2 Up 0 0 1 2 3 4
Te 1/1/1/3 Up 0 0 1 2 3 4
DellEMC#
To view a dampening summary for the entire system, use the show interfaces dampening summary command from
EXEC Privilege mode.
DellEMC# show interfaces dampening summary
20 interfaces are configured with dampening. 3 interfaces are currently suppressed.
Following interfaces are currently suppressed:
Te 1/1/1/2
Te 1/1/1/3
Te 1/1/1/4
DellEMC#
Clearing Dampening Counters
To clear dampening counters and accumulated penalties, use the following command.
● Clear dampening counters.
clear dampening
DellEMC# clear dampening interface Te 1/1/1/1
DellEMC#show interfaces dampening tengigabitethernet 1/1/1/1
Interface Supp Flaps Penalty Half-Life Reuse Suppress Max-Sup
State
Te 1/1/1/1 Up 0 0 1 2 3 4
DellEMC#
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Interfaces