Which switch feature restricts which MAC addresses can connect to a switch port and can limit the number of allowed MAC addresses and specify a violation action?

Which switch feature restricts which MAC addresses can connect to a switch port and can limit the number of allowed MAC addresses and specify a violation action?

• A. Layer 3 Switch
• B. Port Security
• C. Sticky MAC
• D. BPDU Guard

Answer: (B)

Port security is the feature that controls which devices may connect to a switch port by limiting how many MAC addresses can be learned on that port and by defining what happens when a violation occurs. You can set a maximum number of MAC addresses for a port, and you can enable sticky MAC to learn addresses dynamically and store them in the running configuration so they persist. When the limit is reached, the configured violation action kicks in—shutdown (disable the port until you intervene), restrict (drop frames from unknown addresses and generate logs), or protect (drop frames from unknown addresses without changing the port state). This combination directly enforces per-port device access and the appropriate response to violations, making it the correct choice. The other features serve different purposes: a Layer 3 switch provides routing capabilities, sticky MAC is a mechanism used within port security to learn addresses, and BPDU Guard protects against rogue BPDU frames rather than per-port MAC address restrictions.

Port security is the feature that controls which devices may connect to a switch port by limiting how many MAC addresses can be learned on that port and by defining what happens when a violation occurs. You can set a maximum number of MAC addresses for a port, and you can enable sticky MAC to learn addresses dynamically and store them in the running configuration so they persist. When the limit is reached, the configured violation action kicks in—shutdown (disable the port until you intervene), restrict (drop frames from unknown addresses and generate logs), or protect (drop frames from unknown addresses without changing the port state). This combination directly enforces per-port device access and the appropriate response to violations, making it the correct choice. The other features serve different purposes: a Layer 3 switch provides routing capabilities, sticky MAC is a mechanism used within port security to learn addresses, and BPDU Guard protects against rogue BPDU frames rather than per-port MAC address restrictions.