What is the purpose of ARP?

What is the purpose of ARP?

• A. Maps IP network addresses to MAC addresses
• B. Converts domain names to IPs
• C. Encrypts traffic
• D. Assigns IP addresses via DHCP

Answer: (A)

ARP translates an IPv4 address into the MAC address of the device on the local network. On an Ethernet LAN, devices need the hardware (MAC) address to actually deliver a frame, even though routing uses the IP address. When a host wants to send to a certain IP, it first checks its ARP cache. If it doesn’t know the MAC, it broadcasts an ARP request asking, “Who has this IP? tell me your MAC.” The device that owns that IP replies with its MAC address, and the sender caches this mapping for future use. This lets IP traffic be carried over the local link by the correct hardware address. ARP is not about domain names (DNS), encrypting traffic, or assigning IPs (DHCP).

ARP translates an IPv4 address into the MAC address of the device on the local network. On an Ethernet LAN, devices need the hardware (MAC) address to actually deliver a frame, even though routing uses the IP address. When a host wants to send to a certain IP, it first checks its ARP cache. If it doesn’t know the MAC, it broadcasts an ARP request asking, “Who has this IP? tell me your MAC.” The device that owns that IP replies with its MAC address, and the sender caches this mapping for future use. This lets IP traffic be carried over the local link by the correct hardware address. ARP is not about domain names (DNS), encrypting traffic, or assigning IPs (DHCP).