8 /* * Address Resolution Protocol. * * See RFC 826 for protocol description. ARP packets are variable * in size; the arphdr structure defines the fixed-length portion. * Protocol type values are the same as those for 10 Mb/s Ethernet. * It is followed by the variable-sized fields ar_sha, arp_spa, * arp_tha and arp_tpa in that order, according to the lengths * specified. Field names used correspond to RFC 826. */