Introduction - If you have any usage issues, please Google them yourself
In network communication, the application of the source host know the destination host IP address and port number, but do not know the hardware address of the destination host, the packet is received by the first card to get to the upper layer protocol, if the received data packets and the machine hardware address does not directly discard. Therefore, the hardware address of the destination host must be obtained before communication. The ARP protocol does that. The source host sends a ARP request, ask "IP address is 192.168.0.1 hardware address is the number, and the request is broadcast to the local network (Ethernet frame header hardware address fill FF:FF:FF:FF:FF:FF said broadcast), the destination host receives the broadcast ARP request, consistent with the machine IP address is the send a ARP response packet to the source host, will own hardware address in response to the package