Match each STP-related term or feature to its most accurate function.

Technical deep dive

How to think about this question

Spanning Tree Protocol (STP) is a Layer 2 network protocol designed to prevent loops in Ethernet networks by creating a loop-free logical topology. The root bridge is the central reference point in the STP topology, elected based on the lowest bridge ID. All switches calculate their best path to the root bridge, and ports are assigned roles such as root port, designated port, or blocked port to maintain a loop-free environment. STP dynamically blocks redundant paths while allowing a single active path between any two network devices. A root port is the single port on a non-root switch that provides the lowest-cost path back to the root bridge. PortFast is a Cisco feature applied to edge ports that immediately transitions the port to the forwarding state, bypassing the usual listening and learning states to speed up device connectivity. BPDU Guard is a security feature that disables a PortFast-enabled port if it receives a Bridge Protocol Data Unit (BPDU), protecting the network from potential loops caused by unauthorized switches or devices. A common exam trap is confusing the roles and functions of STP terms, such as assuming PortFast ports participate in STP calculations or that BPDU Guard is optional for all edge ports. In practice, PortFast ports do not send BPDUs and should only be enabled on ports connected to end devices. BPDU Guard protects the network by shutting down ports that receive unexpected BPDUs, preventing potential topology changes or loops. Understanding these operational roles is critical for correctly answering STP-related questions on the CCNA exam.

More questions from this exam

Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.

FAQ

Questions learners often ask