Guidelines And Limitations - Cisco nexus 5000 series Cli Configuration Manual

Guidelines and Limitations

S e n d f e e d b a c k t o n x 5 0 0 0 - d o c f e e d b a c k @ c i s c o . c o m
Figure 1-1
The traffic storm control threshold numbers and the time interval allow the traffic storm control
algorithm to work with different levels of packet granularity. For example, a higher threshold allows
more packets to pass through.
Traffic storm control on the Cisco Nexus 5000 Series switch is implemented in the hardware. The traffic
storm control circuitry monitors packets that pass from a Layer 2 interface to the switching bus. Using
the Individual/Group bit in the packet destination address, the circuitry determines if the packet is
unicast or broadcast, tracks the current count of packets within the 10-microsecond interval, and filters
out subsequent packets when a threshold is reached.
Traffic storm control uses a bandwidth-based method to measure traffic. You set the percentage of total
available bandwidth that the controlled traffic can use. Because packets do not arrive at uniform
intervals, the 10-microsecond interval can affect the operation of traffic storm control.
The following are examples of how traffic storm control operation is affected:
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By default, Cisco NX-OS takes no corrective action when the traffic exceeds the configured level.
Guidelines and Limitations
When configuring the traffic storm control level, follow these guidelines and limitations:
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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
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Broadcast Suppression
If you enable broadcast traffic storm control, and broadcast traffic exceeds the level within the
10-microsecond interval, traffic storm control drops all broadcast traffic until the end of the interval.
If you enable multicast traffic storm control, and the multicast traffic exceeds the level within the
10-microsecond interval, traffic storm control drops all multicast traffic until the end of the interval.
If you enable broadcast and multicast traffic storm control, and broadcast traffic exceeds the level
within the 10-microsecond interval, traffic storm control drops all broadcast traffic until the end of
the interval.
If you enable broadcast and multicast traffic storm control, and multicast traffic exceeds the level
within the 10-microsecond interval, traffic storm control drops all multicast traffic until the end of
the interval.
You can configure traffic storm control on a port-channel interface.
Specify the level as a percentage of the total interface bandwidth:
– The level can be from 0 to 100.
– The optional fraction of a level can be from 0 to 99.
Chapter 1 Configuring Traffic Storm Control
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