Which protocol helps to prevent loops in a network of switches?

The correct answer is Spanning Tree Protocol because it is specifically designed to prevent network loops in Ethernet networks that consist of switches. In a network topology where multiple paths exist between switches, loops can occur, leading to broadcast storms and network instability. Spanning Tree Protocol (STP) works by identifying and blocking redundant paths, creating a loop-free logical topology.

STP operates by electing a root bridge and then determining the shortest path from the root to all other switches. It disables any links that could form a loop while maintaining active paths. This functionality is crucial for maintaining reliable network communication and ensuring efficient data flow.

Other protocols listed, such as Internet Control Message Protocol, File Transfer Protocol, and Hypertext Transfer Protocol, serve different purposes within networking. ICMP is primarily used for error messages and operational queries, FTP is utilized for transferring files, and HTTP is for transmitting web pages. None of these protocols contribute to loop prevention in switch networks like STP does.