Configuring Gratuitous Arp - H3C S5120-SI Series Operation Manual

[Switch] interface GigabitEthernet 1/0/1
[Switch-GigabitEthernet1/0/1] port access vlan 10
[Switch-GigabitEthernet1/0/1] quit
# Create interface VLAN-interace 10 and configure its IP address.
[Switch] interface vlan-interface 10
[Switch-vlan-interface10] ip address 192.168.1.2 8
[Switch-vlan-interface10] quit
# Configure a static ARP entry with IP address 192.168.1.1 and MAC address 00e0-fc01-0000. The
outgoing interface corresponding to the static ARP entry is GigabitEthernet 1/0/1 belonging to VLAN 10.
[Switch] arp static 192.168.1.1 00e0-fc01-0000 10 GigabitEthernet 1/0/1
# View information about static ARP entries.
[Switch] display arp static
IP Address
192.168.1.1

Configuring Gratuitous ARP

Introduction to Gratuitous ARP
In a gratuitous ARP packet, the sender IP address and the target IP address are both the IP address of
the device issuing the packet, the sender MAC address is the MAC address of the device, and the target
MAC address is the broadcast address ff:ff:ff:ff:ff:ff.
A device implements the following functions by sending gratuitous ARP packets:
Determining whether its IP address is already used by another device.
Informing other devices about the change of its MAC address so that they can update their ARP
entries.
A device receiving a gratuitous ARP packet adds the information carried in the packet to its own
dynamic ARP table if it finds no corresponding ARP entry exists in the cache.
Configuring Gratuitous ARP
Follow these steps to configure gratuitous ARP:
To do...
Enter system view
Enable the device to send
gratuitous ARP packets when
receiving ARP requests from
another network segment
Enable the gratuitous ARP
packet learning function
Type: S-Static D-Dynamic
MAC Address VLAN ID
00e0-fc01-0000 10
Use the command...
system-view
gratuitous-arp-sending
enable
gratuitous-arp-learning
enable
Interface
GE1/0/1
—
Required
By default, a device cannot
send gratuitous ARP packets
when receiving ARP requests
from another network segment.
Optional
Enabled by default.
1-6
Aging Type
N/A S
Remarks