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Chapter 43 ARP Learning
XGS-4526/4528F/4728F User’s Guide
382
43.1.2.1 ARP-Reply
By default, the Switch is in ARP-Reply learning mode and updates the ARP table
only with the ARP replies to the ARP requests sent by the Switch. This can help
prevent ARP spoofing.
In the following example, the Switch does not have IP address and MAC address
mapping information for hosts A and B in its ARP table, and host A wants to ping
host B. Host A sends an ARP request to the Switch and then sends an ICMP
request after getting the ARP reply from the Switch. The Switch finds no matched
entry for host B in the ARP table and broadcasts the ARP request to all the devices
on the LAN. When the Switch receives the ARP reply from host B, it updates its
ARP table and also forwards host A’s ICMP request to host B. After the Switch gets
the ICMP reply from host B, it sends out an ARP request to get host A’s MAC
address and updates the ARP table with host A’s ARP reply. The Switch then can
forward host B’s ICMP reply to host A.
43.1.2.2 Gratuitous-ARP
A gratuitous ARP is an ARP request in which both the source and destination IP
address fields are set to the IP address of the device that sends this request and
the destination MAC address field is set to the broadcast address. There will be no
reply to a gratuitous ARP request.
A device may send a gratuitous ARP packet to detect IP collisions. If a device
restarts or its MAC address is changed, it can also use gratuitous ARP to inform
A
B
ARP Request
ARP Reply
ICMP Request
ARP Request
ARP Reply
ICMP Request
ICMP Reply
ARP Request
ARP Reply
ICMP Reply
Содержание XGS-4528F
Страница 2: ......
Страница 8: ...Safety Warnings XGS 4526 4528F 4728F User s Guide 8...
Страница 24: ...Table of Contents XGS 4526 4528F 4728F User s Guide 24...
Страница 25: ...25 PART I User s Guide...
Страница 26: ...26...
Страница 32: ...Chapter 1 Getting to Know Your Switch XGS 4526 4528F 4728F User s Guide 32...
Страница 36: ...Chapter 2 Hardware Installation and Connection XGS 4526 4528F 4728F User s Guide 36...
Страница 93: ...93 PART II Technical Reference...
Страница 94: ...94...
Страница 100: ...Chapter 7 System Status and Port Statistics XGS 4526 4528F 4728F User s Guide 100...
Страница 116: ...Chapter 8 Basic Setting XGS 4526 4528F 4728F User s Guide 116...
Страница 136: ...Chapter 9 VLAN XGS 4526 4528F 4728F User s Guide 136...
Страница 140: ...Chapter 10 Static MAC Forward Setup XGS 4526 4528F 4728F User s Guide 140...
Страница 172: ...Chapter 14 Bandwidth Control XGS 4526 4528F 4728F User s Guide 172...
Страница 186: ...Chapter 17 Link Aggregation XGS 4526 4528F 4728F User s Guide 186...
Страница 196: ...Chapter 18 Port Authentication XGS 4526 4528F 4728F User s Guide 196...
Страница 214: ...Chapter 21 Policy Rule XGS 4526 4528F 4728F User s Guide 214...
Страница 258: ...Chapter 25 AAA XGS 4526 4528F 4728F User s Guide 258...
Страница 282: ...Chapter 26 IP Source Guard XGS 4526 4528F 4728F User s Guide 282...
Страница 314: ...Chapter 32 Error Disable XGS 4526 4528F 4728F User s Guide 314...
Страница 318: ...Chapter 33 Private VLAN XGS 4526 4528F 4728F User s Guide 318...
Страница 322: ...Chapter 34 Static Route XGS 4526 4528F 4728F User s Guide 322...
Страница 330: ...Chapter 36 RIP XGS 4526 4528F 4728F User s Guide 330...
Страница 386: ...Chapter 43 ARP Learning XGS 4526 4528F 4728F User s Guide 386...
Страница 396: ...Chapter 45 Maintenance XGS 4526 4528F 4728F User s Guide 396...
Страница 442: ...Chapter 49 Cluster Management XGS 4526 4528F 4728F User s Guide 442...
Страница 446: ...Chapter 50 MAC Table XGS 4526 4528F 4728F User s Guide 446...
Страница 450: ...Chapter 51 IP Table XGS 4526 4528F 4728F User s Guide 450...
Страница 454: ...Chapter 53 Routing Table XGS 4526 4528F 4728F User s Guide 454...
Страница 462: ...Chapter 55 Troubleshooting XGS 4526 4528F 4728F User s Guide 462...
Страница 472: ...Chapter 56 Product Specifications XGS 4526 4528F 4728F User s Guide 472...
Страница 480: ...Appendix B Legal Information XGS 4526 4528F 4728F User s Guide 480...