Operation Manual – ARPH3C S7500 Series Ethernet Switches Chapter 1 ARP Configuration1-2Table 1-1 describes the fields of an ARP packet.Table 1-1 Description on the fields of an ARP packetField DescriptionHardware Type Type of the hardware interface. See Table 1-2 forthe valid values of this field.Protocol type Type of the protocol address to be mapped. For IPaddress, the value of this field is 0x0800.Hardware address length Length of the hardware address (in bytes)Protocol address length Length of the protocol address (in bytes)Operation codeType of the packet, which can be:z 1: ARP requestz 2: ARP replyz 3: RARP requestz 4: RARP replySender hardware address Hardware address of the senderSender IP address IP address of the senderTarget hardware address This field is null for an ARP request, and is thehardware address of the receiver for an ARP reply.Target IP address IP address of the receiverTable 1-2 Values of the hardware type fieldValue Description1 Ethernet2 Experimental Ethernet3 X.254 Proteon ProNET (Token Ring)5 Chaos6 IEEE 802.x7 ARC network1.1.3 ARP TableIn an Ethernet network, two hosts must know each other’s MAC address for them tocommunicate with each other. For this reason, each host on the network maintains anARP table, which contains some lately used IP address-to-MAC address mappingentries. Note that this manual only introduces basic implementation of ARP table.
