How does ARP obtain MAC addresses of devices on a network?

How does ARP obtain MAC addresses of devices on a network?

• A. By sending a direct request to the device
• B. By querying the DNS server
• C. By broadcasting a query over the network
• D. By analyzing previous network connections

Answer: (C)

ARP, or Address Resolution Protocol, obtains MAC addresses of devices on a network by broadcasting a query over the network. When a device wants to communicate with another device on the same local network but only knows its IP address, it uses ARP to discover the corresponding MAC address. The ARP process begins when the device sends out an ARP request packet in the form of a broadcast message. This packet includes the target IP address for which the MAC address is needed. All devices on the local network receive this broadcast, but only the device with the matching IP address will respond. It sends back an ARP reply containing its MAC address. This method is efficient because it allows devices to dynamically learn the MAC addresses of others without needing any prior knowledge or centralized directory, making it a fundamental component of local network communications. The other methods mentioned are not how ARP functions. Sending a direct request to a device implies a unicast communication that doesn't utilize the broadcast mechanism ARP is designed around. Querying a DNS server pertains to resolving domain names to IP addresses, not MAC addresses. Analyzing previous network connections could provide some insight into MAC addresses, but it is not a standardized or reliable method for resolving current addresses as ARP does.

ARP, or Address Resolution Protocol, obtains MAC addresses of devices on a network by broadcasting a query over the network. When a device wants to communicate with another device on the same local network but only knows its IP address, it uses ARP to discover the corresponding MAC address.

The ARP process begins when the device sends out an ARP request packet in the form of a broadcast message. This packet includes the target IP address for which the MAC address is needed. All devices on the local network receive this broadcast, but only the device with the matching IP address will respond. It sends back an ARP reply containing its MAC address. This method is efficient because it allows devices to dynamically learn the MAC addresses of others without needing any prior knowledge or centralized directory, making it a fundamental component of local network communications.

The other methods mentioned are not how ARP functions. Sending a direct request to a device implies a unicast communication that doesn't utilize the broadcast mechanism ARP is designed around. Querying a DNS server pertains to resolving domain names to IP addresses, not MAC addresses. Analyzing previous network connections could provide some insight into MAC addresses, but it is not a standardized or reliable method for resolving current addresses as ARP does.