Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2InfrastructureMedium
A network administrator is troubleshooting an intermittent connectivity issue for several devices in a specific VLAN. The devices are connected to a Cisco Catalyst 9300 switch. The administrator suspects a broadcast storm might be occurring. Which Layer 2 feature, when enabled, can help mitigate the impact of excessive broadcast traffic?
- ABPDU Guard
- BPortFast
- CVLAN Tagging (802.1Q)
- DStorm Control
Show answer & explanationAnswer & explanation
Correct answer: D. Storm Control
Storm Control is a Layer 2 feature that monitors incoming traffic levels on a port and drops packets when a configured threshold for broadcast, multicast, or unknown unicast traffic is exceeded. This directly mitigates broadcast storms.
Why the other options are wrong
- A. BPDU Guard shuts down a port if it receives a BPDU, preventing unauthorized switches, not broadcast storms.
- B. PortFast speeds up STP convergence on access ports but does not prevent broadcast storms.
- C. VLAN Tagging segments networks but does not inherently prevent broadcast storms within a VLAN.
Storm Control
A Layer 2 feature on Cisco switches that prevents traffic storms by monitoring incoming traffic levels and suppressing excessive broadcast, multicast, or unknown unicast traffic.
- Mitigates broadcast, multicast, and unicast storms.
- Configured per interface.
- Uses thresholds (e.g., percentage or pps) to trigger.
Memory trick: Storm Control stops the flood before it drowns the network.