25
ARP C
ONFIGURATION
Introduction to ARP
Address resolution protocol (ARP) is used to resolve IP addresses into MAC addresses.
Necessity of the Address
Resolution
IP address is used on the network layer and cannot be used directly for
communication, because network devices can only identify MAC addresses. To enable
packets travel on the network layer to reach the destination host, the MAC address of
the host is required. Therefore, before sending a packet, the sender needs to resolve
the IP address of the destination into the corresponding MAC address.
ARP Packet Structure
ARP packets are classified into ARP request packets and ARP reply packets. Table 162
illustrates the structure of these two types of ARP packets.
■
As for an ARP request packet, all the fields except the hardware address of the
receiver field are set. The hardware address of the receiver is what the sender
request for.
■
As for an ARP reply packets, all the fields are set.
Table 163 describes the fields of an ARP packet.
Table 162
Structure of an ARP request/reply packet
Hardware type (16 bits)
Protocol type (16 bits)
Length of hardware address
Length of protocol address
Operator (16 bits)
IP Address of the sender
Hardware address of the sender
IP Address of the receiver
Hardware address of the receiver
Table 163
Description on the fields of an ARP packet
Field
Description
Hardware Type
Identifies the type of the hardware interface.
Refer to Table 164 for the information about
the field values.
Protocol type
Identifies the type of the protocol used by the
sending device. In TCP/IP, it is usually EtherType.
Length of the 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:
1: ARP request packets
2: ARP reply packets
3: RARP request packets
4: RARP reply packets
Hardware address of the sender
Hardware address of the sender
IP address of the sender
IP address of the sender
Summary of Contents for 4200G 12-Port
Page 10: ...8 CONTENTS...
Page 14: ...4 ABOUT THIS GUIDE...
Page 46: ...32 CHAPTER 5 LOGGING IN THROUGH WEB BASED NETWORK MANAGEMENT SYSTEM...
Page 48: ...34 CHAPTER 6 LOGGING IN THROUGH NMS...
Page 60: ...46 CHAPTER 9 VLAN CONFIGURATION...
Page 64: ...50 CHAPTER 10 MANAGEMENT VLAN CONFIGURATION...
Page 80: ...66 CHAPTER 13 GVRP CONFIGURATION...
Page 98: ...84 CHAPTER 15 LINK AGGREGATION CONFIGURATION...
Page 112: ...98 CHAPTER 18 MAC ADDRESS TABLE MANAGEMENT...
Page 126: ...112 CHAPTER 19 LOGGING IN THROUGH TELNET...
Page 162: ...148 CHAPTER 20 MSTP CONFIGURATION...
Page 274: ...260 CHAPTER 29 IGMP SNOOPING CONFIGURATION...
Page 276: ...262 CHAPTER 30 ROUTING PORT JOIN TO MULTICAST GROUP CONFIGURATION...
Page 298: ...284 CHAPTER 33 SNMP CONFIGURATION...
Page 304: ...290 CHAPTER 34 RMON CONFIGURATION...
Page 338: ...324 CHAPTER 36 SSH TERMINAL SERVICES...
Page 356: ...342 CHAPTER 38 FTP AND TFTP CONFIGURATION...
Page 365: ...Information Center Configuration Example 351 S4200G terminal logging...
Page 366: ...352 CHAPTER 39 INFORMATION CENTER...
Page 378: ...364 CHAPTER 40 BOOTROM AND HOST SOFTWARE LOADING...
Page 384: ...370 CHAPTER 41 Basic System Configuration and Debugging...
Page 388: ...374 CHAPTER 43 NETWORK CONNECTIVITY TEST...
Page 406: ...392 CHAPTER 45 CONFIGURATION OF NEWLY ADDED CLUSTER FUNCTIONS...