Dampening is a configurable mechanism that excludes unstable links whose state changes too frequently from path calculation. When determining link instability, the following state changes are taken into account:
UP/LIVE → DOWN/NOT-LIVE.
DOWN/NOT-LIVE → UP/LIVE.
UP/LIVE → UP/NOT-LIVE.
UP/NOT-LIVE → UP/LIVE.
When Dampening is enabled, each state change of the link increases the Penalty value. If the Penalty reaches the threshold within the specified time, access to the link is restricted (its cost is increased 10,000 times for the specified period of time). The value of each of these parameters is specified when you enable Dampening. By default, access to the link is resumed if the state of the link does not change for 10 minutes.
To enable Dampening:
Enable Dampening in one of the following ways:
If you want to enable Dampening for a link that was established from a CPE device, go to the SD-WAN → CPE section, click the CPE device, select the Tunnels tab, and click Management → Dampening next to the link.
If you want to enable Dampening for one of the links in the table of all links, go to the Infrastructure section, click Management → Configuration menu next to the controller, go to the Tunnels section, and click Management → Dampening next to the link.
If you want to enable Dampening for one of the links in the graphic topology with all links, go to the Infrastructure section, click Management → Configuration menu next to the controller, go to the Topology section, click the link, and click Dampening.
This opens a window; in that window, select the Enable check box to enable Dampening on the link. This check box is cleared by default.
In the Maximum suppress time (ms.) field, enter the time, in milliseconds, for which access to the link can be restricted. When the specified time elapses, all Dampening counters on the link are reset. The default setting is 600000.
In the Penalty field, enter the number by which Penalty is incremented when the link changes state. The default setting is 1.
In the Suppress threshold field, enter the Penalty value at which access to the link is restricted. The default setting is 4.
In the Update interval (ms.) field, enter the time in milliseconds during which Penalty must attain the value specified in the Suppress threshold field for access to the link to be restricted. The default setting is 120000.
If you want to view Dampening statistics for a link, click Load statistics.
Click Save.
Dampening is enabled for the link.
If you enabled Dampening for a link established from the CPE device, click Save in the upper part of the settings area to save the CPE device settings.