Broadcast Traffic Suppression Does Not Take Effect
Fault Description
After broadcast traffic suppression is configured on an interface, a broadcast storm caused by broadcast packets still occurs and service traffic is interrupted.
Common Causes
- Broadcast suppression is not configured on interfaces, or the broadcast suppression threshold is set too high.
- Broadcast packets are not discarded on the inbound interface.
- Saving the results of each troubleshooting step is recommended so that, if the troubleshooting fails to correct the fault, you can provide this information to technical support personnel.
- Troubleshooting for unknown multicast and unknown unicast traffic suppression is similar to that for broadcast traffic suppression.
Procedure
- Check that traffic suppression is correctly configured on the related interface.
Run the display flow-suppression interface interface-type interface-number command in the user view to check whether the values of rate mode and set rate value in the broadcast field are appropriate.
- If these values are inappropriate, run the broadcast-suppression { percent-value | packets packets-per-second } command to change broadcast traffic suppression parameters.
- If these values are appropriate, go to step 2.
- Check whether broadcast packets are being discarded in the inbound direction of the interface.
Use the following methods to check whether broadcast packets are being discarded in the inbound direction of the interface:
Run the display interface interface-type interface-number command in the user view to check whether the value of Input bandwidth utilization changes significantly after traffic suppression is configured. Normally, after traffic suppression is configured, bandwidth occupation on an interface decreases if the interface is discarding excess packets. If the value of Input bandwidth utilization does not change or changes only slightly, go to step 3.
Add another interface (interface B) to the same VLAN as the interface (interface A) that is configured with traffic suppression. Then check whether the volume of the outgoing traffic on interface B is the same as the volume of the traffic on interface A. If they are different, packets are not discarded in the inbound direction of interface A. Go to step 3.
- Collect the following information and contact technical support personnel.
- Results of the preceding troubleshooting procedure
- Configuration file, logs, and alarms of the member switch