Administrator Guide

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-te-1/1)#show config
!
interface TengigabitEthernet 1/1
ip address 10.10.19.1/24
dampening 1 2 3 4
no shutdown
R1(conf-if-te-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.
Dell# show interfaces dampening
Interface State Flaps Penalty Half-Life Reuse Suppress Max-Sup
Te 0/0 Up 0 0 57 502 500 20
Te 0/1 Up 2 1 200 20500 1500 300
Te 0/2 Down 4 8 50 30600 2000 120
To view link dampening on a port extender interface.
Dell(conf-if-range-pegi-255/1/36-37)#do show interface
Interface Supp Flaps Penalty Half-Life Reuse Suppress Max-Sup
State
PeGi 255/1/36 Up 0 0 20 200 800 100
PeGi 255/1/37 Up 0 0 20 200 800 100
To view a dampening summary for the entire system, use the show interfaces dampening summary command from EXEC
Privilege mode.
Dell# show interfaces dampening summary
20 interfaces are configured with dampening. 3 interfaces are currently suppressed.
Following interfaces are currently suppressed:
Te 0/2
Te 3/1
Te 4/2
Dell#
422
Interfaces