A network administrator receives complaints of intermittent network connectivity issues.

Spanning Tree Protocol (STP) is designed to detect and prevent Layer 2 loops by blocking redundant paths. If loops are possible in the design, enabling STP ensures network stability.

B. Port security controls endpoint MAC addresses, not loops.

C. Speed limits address bandwidth, not loop prevention.

D. 802.1Q tagging allows VLAN separation but does not resolve loops.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Loop prevention, spanning tree, switch design.