Configuring storm control on an Ethernet interface
Storm control compares broadcast, multicast, and unknown unicast traffic regularly with their respective traffic thresholds on an Ethernet interface. For each type of traffic, storm control provides a lower threshold and a higher threshold.
For management purposes, you can configure the interface to output threshold event traps and log messages when monitored traffic meets one of the following conditions:
Exceeds the upper threshold.
Falls below the lower threshold from the upper threshold.
Depending on your configuration, when a particular type of traffic exceeds its upper threshold, the interface does either of the following:
Blocks this type of traffic, while forwarding other types of traffic—Even though the interface does not forward the blocked traffic, it still counts the traffic. When the blocked traffic drops below the lower threshold, the port begins to forward the traffic.
Goes down automatically—The interface goes down automatically and stops forwarding any traffic. When the blocked traffic is detected dropping below the lower threshold, the port does not forward the traffic. To bring up the interface, use the undo shutdown command or disable the storm control feature.
Any of the storm-constrain, broadcast-suppression, multicast-suppression, and unicast-suppression commands can suppress storm on a port. The broadcast-suppression, multicast-suppression, and unicast-suppression commands suppress traffic in hardware, and have less impact on device performance than the storm-constrain command, which performs suppression in software.
Storm control uses a complete polling cycle to collect traffic data, and analyzes the data in the next cycle. An interface takes one to two polling intervals to take a storm control action.
Configuration guidelines
For the same type of traffic, do not configure the storm constrain command together with any of the broadcast-suppression, multicast-suppression, and unicast-suppression commands. Otherwise, the traffic suppression result is not determined. For more information about the broadcast-suppression, multicast-suppression, and unicast-suppression commands, see "Configuring storm suppression."
Configuration procedure
To configure storm control on an Ethernet interface:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. (Optional.) Set the traffic polling interval of the storm control module. | storm-constrain interval seconds | The default setting is 10 seconds. For network stability, use the default or set a higher traffic polling interval (10 seconds). |
3. Enter Ethernet interface view. | interface interface-type interface-number | N/A |
4. (Optional.) Enable storm control, and set the lower and upper thresholds for broadcast, multicast, or unknown unicast traffic. | storm-constrain { broadcast | multicast | unicast } { pps | kbps | ratio } max-pps-values min-pps-values | By default, storm control is disabled. |
5. Set the control action to take when monitored traffic exceeds the upper threshold. | storm-constrain control { block | shutdown } | By default, storm control is disabled. |
6. (Optional.) Enable the interface to log storm control threshold events. | storm-constrain enable log | By default, the interface outputs log messages when monitored traffic exceeds the upper threshold or falls below the lower threshold from the upper threshold. |
7. (Optional.) Enable the interface to send storm control threshold event traps. | storm-constrain enable trap | By default, the interface sends traps when monitored traffic exceeds the upper threshold or drops below the lower threshold from the upper threshold. |