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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-96803	CISC-RT-000700	SV-105941r1_rule		Medium

Description
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.

Description

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.

STIG	Date
Cisco IOS XR Router RTR Security Technical Implementation Guide	2019-12-20

Details

Check Text ( C-95639r1_chk )
Review the router configuration to verify that storm control is enabled on CE-facing interfaces deploying VPLS as shown in the example below. bridge group L2GROUP bridge-domain L2_BRIDGE_COI1 interface GigabitEthernet0/0/0/2 storm-control unknown-unicast kbps 1200 storm-control multicast kbps 1200 storm-control broadcast kbps 1200 split-horizon group ! If storm control is not enabled at a minimum for broadcast traffic, this is a finding.

Check Text ( C-95639r1_chk )

Review the router configuration to verify that storm control is enabled on CE-facing interfaces deploying VPLS as shown in the example below.

bridge group L2GROUP
bridge-domain L2_BRIDGE_COI1
interface GigabitEthernet0/0/0/2
storm-control unknown-unicast kbps 1200
storm-control multicast kbps 1200
storm-control broadcast kbps 1200
split-horizon group
!

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

Fix Text (F-102483r1_fix)
Configure storm control for each CE-facing interface as shown in the example below. RP/0/0/CPU0:R3(config)#l2vpn RP/0/0/CPU0:R3(config-l2vpn)#bridge group L2GROUP RP/0/0/CPU0:R3(config-l2vpn-bg)# bridge-domain L2_BRIDGE_COI1 RP/0/0/CPU0:R3(config-l2vpn-bg-bd)#interface GigabitEthernet0/0/0/2 RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#storm-control broadcast kbps 1200 RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#storm-control multicast kbps 1200 RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#storm-control unknown-unicast kbps 1200 RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#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.

Fix Text (F-102483r1_fix)

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

RP/0/0/CPU0:R3(config)#l2vpn
RP/0/0/CPU0:R3(config-l2vpn)#bridge group L2GROUP
RP/0/0/CPU0:R3(config-l2vpn-bg)# bridge-domain L2_BRIDGE_COI1
RP/0/0/CPU0:R3(config-l2vpn-bg-bd)#interface GigabitEthernet0/0/0/2
RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#storm-control broadcast kbps 1200
RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#storm-control multicast kbps 1200
RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#storm-control unknown-unicast kbps 1200
RP/0/0/CPU0:R3(config-l2vpn-bg-bd-ac)#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.