What is the purpose of Spanning Tree Protocol (STP) in Ethernet networks?

• A. To increase network speed by prioritizing active links.
• B. To provide redundant paths without loops.
• C. To prevent switching loops by disabling redundant paths and maintaining a loop-free topology.
• D. To encrypt control traffic between switches.

Answer: (C)

Spanning Tree Protocol is about preventing loops in Ethernet networks by creating a loop-free logical topology. It does this by electing a root bridge and determining a single, best path from each switch to that root. Each switch then designates one port as the forward path toward the root (the root port) and marks other overlapping or redundant links as blocked so they do not forward traffic. By keeping those redundant paths in a non-forwarding state, the network avoids switching loops that can cause broadcast storms and duplicate frames. If a link or switch fails, the protocol can activate a blocked path to reestablish connectivity, providing redundancy without letting loops form. It’s not about increasing speed or encrypting traffic; it’s about maintaining a stable, loop-free network topology while still offering backup paths.