CHAPTER
36-1
Software Configuration Guide—Release 12.2(25)SG
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36
Configuring Storm Control
This chapter describes how to configure port-based traffic control on the Catalyst 4500 series switch.
Note For complete syntax and usage information for the switch commands used in this chapter, refer to the
Catalyst 4500 Series Switch Cisco IOS Command Reference and related publications at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/index.htm.
This chapter consists of these sections:
Overview of Storm Control, page 36-1
Enabling Storm Control, page 36-3
Disabling Storm Control, page 36-4
Displaying Storm Control, page 36-4
Multicast Storm Control, page 36-6

Overview of Storm Control

This section contains the following subsections:
Hardware-based Storm Control Implementation, page 36-2
Software-based Storm Control Implementation, page 36-2
Storm control prevents LAN interfaces from being disrupted by a broadcast storm . A broadcast storm
occurs when broadcast packets flood the subnet, creating excessive traffic and degrading network
performance. Errors in the protocol-stack implementation or in the network configuration can cause a
broadcast storm.
Note Storm control is supported in hardware on all ports on the WS-X4 516 supervisor engine. In contrast, the
supervisor engines WS-X4515, WS-X4014, and WS-X4013+ support storm control in hardware on
non-blocking gigabit ports and in software on all other ports, implying that the counters for these
interfaces are approximate and computed. Multicast storm control is only supported on the WS-X4516
supervisor engine.