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V-221044

CAT II (Medium)

The Cisco PE switch providing Virtual Private LAN Services (VPLS) must be configured to have traffic storm control thresholds on CE-facing interfaces.

Rule ID

SV-221044r622190_rule

STIG

Cisco IOS XE Switch RTR Security Technical Implementation Guide

Version

V3R4

CCIs

CCI-001095

Discussion

A traffic storm occurs when packets flood a VPLS bridge, creating excessive traffic and degrading network performance. Traffic storm control prevents VPLS bridge disruption by suppressing traffic when the number of packets reaches configured threshold levels. Traffic storm control monitors incoming 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 CE-facing interfaces deploying VPLS as shown in the example below:

interface GigabitEthernet3
 no switchport
 no ip address
 service instance 10 ethernet
 encapsulation untagged
 bridge-domain 100
 storm-control broadcast cir 12000000 
 !
!

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

Fix Text

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

SW1(config)#int g3
SW1(config-if)#service instance 10 ethernet 
SW1(config-if-srv)#storm-control broadcast cir 12000000
SW1(config-if-srv)#end

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