Which feature shuts down a port when a BPDU frame is received?

Which feature shuts down a port when a BPDU frame is received?

• A. Port Security
• B. Sticky MAC
• C. 10BASE-T
• D. BPDU Guard

Answer: (D)

Shutting down a port when a BPDU frame is received is a defense against rogue or misconfigured switches. This behavior is what BPDU Guard provides. On ports that are intended to be connected to end devices (often with PortFast enabled), BPDUs should not be coming from those devices. If a BPDU is detected, BPDU Guard places the port into an error-disabled state to prevent a potential loop or topology problem, and the port must be re-enabled by an administrator (or automatically after a recovery timer, if configured). This specific reaction to receiving a BPDU is why BPDU Guard is the best choice here. Port Security deals with limiting the number or set of MAC addresses on a port and can shut down on MAC violations, but not due to BPDU reception. Sticky MAC is simply a method within port security to lock learned addresses. 10BASE-T is just a physical-layer Ethernet standard, not a mechanism for reacting to BPDUs.

Shutting down a port when a BPDU frame is received is a defense against rogue or misconfigured switches. This behavior is what BPDU Guard provides. On ports that are intended to be connected to end devices (often with PortFast enabled), BPDUs should not be coming from those devices. If a BPDU is detected, BPDU Guard places the port into an error-disabled state to prevent a potential loop or topology problem, and the port must be re-enabled by an administrator (or automatically after a recovery timer, if configured). This specific reaction to receiving a BPDU is why BPDU Guard is the best choice here.

Port Security deals with limiting the number or set of MAC addresses on a port and can shut down on MAC violations, but not due to BPDU reception. Sticky MAC is simply a method within port security to lock learned addresses. 10BASE-T is just a physical-layer Ethernet standard, not a mechanism for reacting to BPDUs.