Cisco Certified Support Technician (CCST) NetworkingNetwork AccessEasy
A network technician is configuring a new Cisco Catalyst switch and needs to ensure that only a single MAC address can be learned on a specific access port. If a different MAC address attempts to connect, the port should shut down immediately. Which feature should the technician configure?
- ALink Aggregation Control Protocol (LACP)
- BPort Security
- CVLAN Trunking Protocol (VTP)
- DSpanning Tree Protocol (STP)
Show answer & explanationAnswer & explanation
Correct answer: B. Port Security
Port Security allows administrators to restrict the number of MAC addresses learned on a switch port and define actions when violations occur. In this case, it ensures only one allowed MAC address can connect, shutting down the port if a violation is detected.
Why the other options are wrong
- A. LACP bundles multiple physical links into a single logical link for increased bandwidth and redundancy, unrelated to MAC address restriction.
- C. VTP manages VLANs across multiple switches but does not control MAC address learning on individual ports.
- D. STP prevents loops in a switched network but does not restrict MAC addresses on a port.
Port Security
A Cisco switch feature that allows administrators to restrict input to an interface by limiting and identifying MAC addresses of allowed devices.
- Restricts MAC addresses on a port
- Can specify maximum MAC addresses
- Violation modes include shutdown, restrict, protect
Memory trick: Secure your port, lock out the foreign MAC.