ARP(Address Resolution Protocol)

ARP is a protocol belonging to Layer 3 network layer in OSI Layer and is used to know the MAC address of another PC or server for communication. And the MAC address translation operation for the destination ip address. It is transmitted in the form attached after the Ethernet header, and the data transmission method uses broadcast.

ARP is used to know the MAC address, and RARP is used to know the ip.

Hardware Type : This field defines the type of network and is set to 0x0001 for Ethernet.

Protocol Type : Protocol, and in case of IPv4, 0x0800 is set.

Hardware Length : This field defines the length of the MAC address, and Ethernet is set to 6 (bytes).

Protocol Length : This field defines the length of the protocol, and IPv4 is set to 4 (bytes).

Operation : This field indicates the type of packet, 1 for Request and 2 for Reply.

Sender Hardware Address : The sender MAC address is set.

Sender IP Address : The sender IP address is set.

Target Hardware Address : The destination MAC address is set, but when it is a request, 0 is set because there is no address value.

Target IP Address : The destination IP address is set.