A regional planning commission needs a predictable STP root for the civic core and must stop a rogue closet switch from winning root. Which feature specifically guards against superior BPDUs on a designated port toward that closet?
Select an answer to reveal the explanation.
Short Explanation
Root guard is the bouncer at the civic core’s VIP door: a closet switch waving a better priority card gets stopped, not promoted. Put it on distribution ports facing untrusted closets so the planned root stays planned.
Full Explanation
Root guard is applied on ports where a superior BPDU should never be accepted; if one arrives, the port enters a root-inconsistent state instead of allowing the attached switch to become root. That protects a designed root bridge in the civic core from rogue or misconfigured closet switches. PortFast is for edge ports and does not protect root election, while UDLD and VTP do not enforce STP root policy. Pair intentional root placement with root guard on downlinks facing untrusted closets.