ARP datagram format

 

ARP datagram format

Note that the source MAC address and target MAC address appear each time in the Ethernet header and ARP request. It is unnecessary for the link layer to be Ethernet, however, if the link layer is another type of network, it may be necessary.

Ethernet Destination Address: the destination MAC address

Ethernet Source Address: source MAC address

Frame Type: Upper-layer protocol type. 0x0806 indicates ARP

Hardware type: indicates the link layer network type. 1 is Ethernet

Protocol type: the address type to be converted. 0x0800 is the IP address

Hardware address length: ethernet address length (generally 6 bytes)