H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – ARP
H3C S7500 Series Ethernet Switches Chapter 1
ARP Configuration
1-2
Table 1-1 describes the fields of an ARP packet.
Table 1-1 Description on the fields of an ARP packet
Field Description
Hardware Type
Type of the hardware interface. See
Table 1-2 for
the valid values of this field.
Protocol type
Type of the protocol address to be mapped. For IP
address, 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 code
Type of the packet, which can be:
z 1: ARP request
z 2: ARP reply
z 3: RARP request
z 4: RARP reply
Sender hardware address Hardware address of the sender
Sender IP address IP address of the sender
Target hardware address
This field is null for an ARP request, and is the
hardware address of the receiver for an ARP reply.
Target IP address IP address of the receiver
Table 1-2 Values of the hardware type field
Value Description
1 Ethernet
2 Experimental Ethernet
3 X.25
4 Proteon ProNET (Token Ring)
5 Chaos
6 IEEE 802.x
7 ARC network
1.1.3 ARP Table
In an Ethernet network, two hosts must know each other’s MAC address for them to
communicate with each other. For this reason, each host on the network maintains an
ARP table, which contains some lately used IP address-to-MAC address mapping
entries. Note that this manual only introduces basic implementation of ARP table.