3Com Switch 4200G Configuration Guide

196 CHAPTER 25: ARP CONFIGURATION
ARP Table In an Ethernet, the MAC addresses of two hosts must be available for the two hosts
to communicate with each other. Each host in an Ethernet maintains an IP
address-to-MAC address mapping table known as ARP mapping table, as illustrated
in Figure 60. An entry of an ARP mapping table contains the IP address and the MAC
address of a host recently communicating with the local host.
Figure 60 An ARP table
Hardware address of the receiver For an ARP request packet, this field is null.
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 164 Description on the values of the hardware type field
Type Description
1 Ethernet
2 Experimental Ethernet
3 X.25
4 Proteon ProNET
5 Chaos
6 IEEE802.X
7 ARC network
Table 163 Description on the fields of an ARP packet (Continued)
Field Description
Entry n
…
Entry 5
Entry 4
Entry 3
Entry 2
Entry 1
TypeIP addressPhysical addressIF index