What function does ARP serve in networking?

ARP, which stands for Address Resolution Protocol, plays a crucial role in networking by resolving IP addresses to their corresponding MAC (Media Access Control) addresses. In a local area network (LAN), devices communicate using MAC addresses at the Data Link layer, while higher-level network protocols such as IP operate at the Network layer.

When a device wants to communicate with another device on the same network using its IP address, it needs to find out the MAC address associated with that IP address. This is where ARP comes into play. The device broadcasts an ARP request on the network asking, "Who has this IP address? Please send me your MAC address." The device that owns that IP address will respond with an ARP reply that contains its MAC address. This allows the requesting device to encapsulate the data in a frame addressed to the target MAC address, enabling successful packet transmission over the network.

The other options relate to different functions that are not performed by ARP. Bandwidth management involves controlling the data rate and allocation of resources, encryption pertains to securing data, and routing packets concerns directing data between different networks, which are responsibilities of other protocols or technologies in networking.