■ 構成 [host]x---------a[host]b----------y[host] #ping b #arp a ■ ARP +--------+ |Hardware| 2 bytes |MAC | |Address | |Type | +--------+ |Protocol| 2 bytes |Address | |Type | +--------+ |Hardware| 1 byte |MAC | |Address | |Size | +--------+ |Protocol| 1 byte |Address | |Size | +--------+ |Op | 2 bytes +--------+ |Sender | 6 bytes (depends on the above size field) |MAC | |Address | +--------+ |Sender