CREST Practitioner Security Analyst (CPSA) Practice

Which protocol is used for resolving IP addresses into MAC addresses?

1. RARP

2. PPP

3. ARP

4. L2TP

The correct answer is: ARP

The correct answer is ARP, which stands for Address Resolution Protocol. ARP is a critical protocol used in networking to map IP addresses to their corresponding MAC (Media Access Control) addresses on a local network. When a device wants to communicate with another device on the same local area network, it needs to know the MAC address of the destination device associated with the IP address it knows. ARP broadcasts a request on the network asking, “Who has IP address X.X.X.X? Tell my MAC address.” The device with the corresponding IP address replies with its MAC address, allowing the original device to communicate with it directly. This process is essential for effective data communication within local networks, as while IP addresses are used for logical addressing and routing, MAC addresses are required for the actual data link layer communication. Therefore, using ARP is fundamental for the proper functioning of a network, enabling devices to locate each other and exchange information efficiently. Other options refer to different protocols with distinct functions. RARP (Reverse Address Resolution Protocol) is used to obtain an IP address from a known MAC address but is not the process by which MAC addresses are resolved from IP addresses. PPP (Point-to-Point Protocol) is utilized for establishing direct connections between two networking nodes