Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2InfrastructureMedium
A network engineer is troubleshooting an intermittent connectivity issue for several end-user devices connected to a Cisco Catalyst switch. Users report that their network access drops randomly for short periods, especially during peak hours. The engineer suspects that excessive broadcast traffic, possibly due to a misconfigured device or a loop, is overwhelming the switch ports. Which Layer 2 feature is designed to prevent service disruptions caused by excessive broadcast, multicast, or unknown unicast traffic on a switch port?
- AStorm Control
- BPort Security
- CSPAN (Switched Port Analyzer)
- DBPDU Guard
Show answer & explanationAnswer & explanation
Correct answer: A. Storm Control
Storm Control is a Layer 2 feature that monitors incoming traffic levels on a switch port and suppresses excessive broadcast, multicast, or unknown unicast traffic to prevent network performance degradation and outages caused by traffic storms.
Why the other options are wrong
- B. Port Security restricts access based on MAC addresses, not traffic volume.
- C. SPAN mirrors traffic for analysis but doesn't prevent traffic storms.
- D. BPDU Guard prevents unauthorized devices from participating in STP, not traffic storms.
Storm Control
A Layer 2 feature on Cisco switches that monitors incoming traffic levels on a port and suppresses excessive broadcast, multicast, or unknown unicast traffic to prevent network performance degradation.
- Prevents broadcast, multicast, or unknown unicast storms.
- Can be configured with thresholds (percentage or bps/pps).
- Can drop excess traffic or shut down the port upon violation.
Memory trick: Layer 2 Shields: Guard Against Storms and Rogue Devices.