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. 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)
Operator
Indicates the type of a data packets, which can be:
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 1-2
Description on the values of the hardware type field
Value
Description
1 Ethernet
2 Experimental
Ethernet
3 X.25
4
Proteon ProNET (Token Ring)
5 Chaos
6 IEEE802.X
7 ARC
network
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 ARP table, where the latest used IP
address-to-MAC address mapping entries are stored. Switch 4210 Family provide the
display arp
command to display the information about ARP mapping entries.
ARP entries in a Switch 4210 can either be static entries or dynamic entries, as described in
Table 1-3
.
