Contents of ARP request

Contents of the ARP request

Here, we will explain the contents of the ARP request in detail.

　Let’s take a look at the contents of the ARP request packet used by computer A to resolve computer E’s MAC address from computer E’s IP address.

The ARP request packet sent by computer A has the following structure.

◆ MAC header

　Although the Ethernet frame header has more than the destination MAC address and source MAC address, only the destination MAC address and source MAC address are shown here.

ARP requests are broadcast. Therefore, the destination MAC address will be “FF:FF:FF:FF:FF:FF”.

◆ ARP header

The header of the ARP request packet looks like this:

Since the target MAC address is unknown, “0” is stored.