3Com WX3000 operation manual Field Description, Value Description, Experimental Ethernet

Figure 1-1ARP message format

Hardware type (16 bits)

Protocol type (16 bits)

Length of hardware address Length of protocol address

Operator (16 bits)

Hardware address of the sender

IP address of the sender

Hardware address of the receiver

IP address of the receiver

Table 1-1 describes the fields of an ARP packet.

Table 1-1Description on the fields of an ARP packet

	Field		Description
	Hardware Type		Type of the hardware interface. Refer to Table 1-2 for the
			information about the field values.
	Protocol type		Type of protocol address to be mapped. 0x0800 indicates an
			IP address.
	Length of hardware address		Hardware address length (in bytes)
	Length of protocol address	Protocol address length (in bytes)
			Indicates the type of a data packets, which can be:
	Operator		z 1: ARP request packets
			z 2: ARP reply packets
			z 3: RARP request packets
			z 4: RARP reply packets
	Hardware address of the sender	Hardware address of the sender
	IP address of the sender	IP address of the sender
	Hardware address of the receiver		z For an ARP request packet, this field is null.
			z For an ARP reply packet, this field carries the hardware
			address of the receiver.
	IP address of the receiver		IP address of the receiver
Table 1-2Description on the values of the hardware type field
	Value		Description
1		Ethernet
2		Experimental Ethernet
3		X.25
4			Proteon ProNET (Token Ring)
		1-2