Which of the following is a primary role of ARP?

The primary role of Address Resolution Protocol (ARP) is to resolve IP addresses to MAC addresses within a local network. When a device wants to communicate with another device on the same local area network (LAN), it must know the MAC address of the destination device since data link layer communication uses MAC addresses, not IP addresses.

When an IP packet is sent out, it includes the destination IP address. If the sending device does not already have the corresponding MAC address in its ARP cache, it sends out an ARP request. This request essentially asks "Who has this IP address? Please send me your MAC address." The device with the matching IP address responds with an ARP reply containing its MAC address. This process allows devices on the same network to communicate effectively.

Managing traffic on a network is a broader network function that involves various protocols and technologies beyond just ARP. Similarly, converting MAC addresses to IP addresses is not the role of ARP; in fact, it is the opposite function. Lastly, ensuring firewall settings are up to date involves security strategies unrelated to the address resolution capabilities of ARP. Thus, the emphasis on ARP's specific function in resolving IP addresses to MAC addresses highlights its critical role in facilitating communication on local networks.