Which of the following protocols is used from PC1 to learn information from some other device on the same network?

(A) ping
(B) ARP
(C) DHCP
(D) DNS

Answer:

ARP is the correct answer. The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link-layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. The job of the ARP is essentially to translate 32-bit addresses to 48-bit addresses and vice-versa. When a new computer joins a LAN, it is assigned a unique IP address to use for identification and communication. When an incoming packet destined for a host machine on a particular LAN arrives at a gateway, the gateway asks the ARP program to find a MAC address that matches the IP address.