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V-220636

CAT III (Low)

The Cisco switch must have Storm Control configured on all host-facing switchports.

Rule ID

SV-220636r648763_rule

STIG

Cisco IOS Switch L2S Security Technical Implementation Guide

Version

V3R1

CCIs

CCI-000366

Discussion

A traffic storm occurs when packets flood a LAN, creating excessive traffic and degrading network performance. Traffic storm control prevents network disruption by suppressing ingress traffic when the number of packets reaches a configured threshold levels. Traffic storm control monitors ingress traffic levels on a port and drops traffic when the number of packets reaches the configured threshold level during any one-second interval.

Check Content

Review the switch configuration to verify that storm control is enabled on all host-facing interfaces as shown in the example below:

interface GigabitEthernet0/3
switchport access vlan 12
storm-control unicast level bps 62000000
storm-control broadcast level bps 20000000

Note: Bandwidth percentage thresholds (via level parameter) can be used in lieu of PPS rate.

If storm control is not enabled at a minimum for broadcast traffic, this is a finding.

Fix Text

Configure storm control for each host-facing interface as shown in the example below:

SW1(config)#int range g0/2 - 8 
SW1(config-if-range)#storm-control unicast bps 62000000 
SW1(config-if-range)#storm-control broadcast level bps 20000000 


Note: The acceptable range is 10000000 -1000000000 for a gigabit Ethernet interface, and 100000000-10000000000 for a 10-gigabit interface. Storm control is not supported on most FastEthernet interfaces.