H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 368)

33-6
[Sysname] arp timer aging 10
[Sysname] vlan 10
[Sysname-vlan10] port gigabitethernet 0/0/10
[Sysname-vlan10] quit
[Sysname] interface vlan-interface 10
[Sysname-vlan-interface10] arp max-learning-num 1000
[Sysname-vlan-interface10] quit
[Sysname] arp static 192.168.1.1 000f-e201-0000 10 gigabitethernet0/0/10
Configuring Gratuitous ARP
Introduction to Gratuitous ARP
A gratuitous ARP packet is a special ARP packet, in which the source IP address and destination IP
address are both the IP address of the sender, the source MAC address is the MAC address of the
sender, and the destination MAC address is a broadcast address.
A device can implement the following functions by sending gratuitous ARP packets:
z
Determining whether its IP address is already used by another device.
z
Informing other devices of its MAC address change so that they can update their ARP entries.
A device receiving a gratuitous ARP packet can add the information carried in the packet to its own
dynamic ARP mapping table if it finds no corresponding ARP entry for the ARP packet in the cache.
Configuring Gratuitous ARP
Follow these steps to configure gratuitous ARP:
To do… Use the command… Remarks
Enter system view system-view —
Enable the device to send
gratuitous ARP packets when
receiving ARP requests from
another network segment
gratuitous-arp-sending enable
Required
By default, a device cannot send
gratuitous ARP packets when
receiving ARP requests from
another network segment.
Enable the gratuitous ARP packet
learning function
gratuitous-arp-learning enable
Required
Enabled by default.
Displaying and Maintaining ARP
To do… Use the command… Remarks
Display the ARP entries in the ARP
mapping table
display arp { { all | dynamic |
static } | vlan vlan-id | interface
interface-type interface-number } [ |
{ begin | exclude | include } string
| count ]
Available in any view
Display the ARP entries for a
specified IP address display arp ip-address [ | { begin |
exclude | include } string ]
Available in any view
Display the aging time for dynamic
ARP entries
display arp timer aging Available in any view