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Cisco Systems IntelligentGigabit Ethernet Switch Modules for the IBMBladeCenter, Software Configuration Guide
24R9746
Chapter15 Configuring Port-Based Traffic Control
Configuring Storm Control
The thresholds can either be expressed as a percentage of the total available bandwidth that can be used
by the broadcast, multicast, or unicast traffic, or as the rate at which the interface receives multicast,
broadcast, or unicast traffic.
When a switch uses the bandwidth-based method, the rising threshold is the percentage of total available
bandwidth associated with multicast, broadcast, or unicast traffic before forwarding is blocked. The
falling threshold is the percentage of total available bandwidth below which the switch resumes normal
forwarding. In general, the higher the level, the less effective the protection against broadcast storms.
When a switch uses traffic rates as the threshold values, the rising and falling thresholds are in packets
per second. The rising threshold is the rate at which multicast, broadcast, and unicast traffic is received
before forwarding is blocked. The falling threshold is the rate below which the switch resumes normal
forwarding. In general, the higher the rate, the less effective the protection against broadcast storms.
Default Storm Control Configuration
By default, broadcast, multicast, and unicast storm control is disabled on the switch. The default action
is to filter traffic and to not send an SNMP trap.
Configuring Storm Control and Threshold Levels
Beginning in privileged EXEC mode, follow these steps to configure storm control and threshold levels:
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Specify the port to configure, and enter interface configuration
mode.
Step3 storm-control {broadcast | multicast |
unicast} level {level [level-low] | pps pps
[pps-low]}
Configure broadcast, multicast, or unicast storm control.
The keywords have these meanings:
•For level, specify the rising threshold level for broadcast,
multicast, or unicast traffic as a percentage of the bandwidth.
The storm control action occurs when traffic utilization reaches
this level.
•(Optional) For level-low, specify the falling threshold level as a
percentage of the bandwidth. This value must be less than the
rising supression value.The normal transmission restarts (if the
action is filtering) when traffic drops below this level.
•For pps pps, specify the rising threshold level for broadcast,
multicast, or unicast traffic in packets per second. The storm
control action occurs when traffic reaches this level.
•(Optional) For pps-low, specify the falling threshold level in
packets per second that can be less than or equal to the ri sing
threshold level. The normal transmission restarts (if the action is
filtering) when traffic drops below this level.
For pps and pps-low, the range is from 0 to 4294967295.