V-220636

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 level. 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. The primary intent of this control is to mitigate the risk of denial-of-service (DoS) attacks, not to arbitrarily restrict bandwidth needed for operations. Consequently, some ports may be configured to operate at full line-rate speed if deemed necessary by the engineer to meet mission requirements. The ultimate responsibility for managing bandwidth to prevent a DoS while ensuring service availability rests with the network engineer.

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. The storm control values in the STIG's example configuration are for illustrative purposes and do not constitute a mandatory value for this setting. Network engineers are responsible for determining and applying appropriate storm control levels based on the specific operational and mission-based bandwidth requirements of each port. A setting must be determined and intentionally configured.

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