3com S7906E 安装指导
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[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 2/0/1 belonging to VLAN
10.
[Switch] arp static 192.168.1.1 00e0-fc01-0000 10 GigabitEthernet 2/0/1
# View information about static ARP entries.
[Switch] display arp static
Type: S-Static D-Dynamic A-Authorized
IP Address MAC Address VLAN ID Interface Aging Type
192.168.1.1 00e0-fc01-0000 10 GE2/0/1 N/A S
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:
z
Determining whether its IP address is already used by another device. If the IP address is already
used, the device issuing the gratuitous ARP packet will be informed by an ARP reply of the conflict.
z
Informing other devices about the change of its MAC address so that they can update their ARP
entries.
Enabling Learning of Gratuitous ARP Packets
With this feature enabled, a device receiving a gratuitous ARP packet adds the sender IP and MAC
addresses carried in the packet to its ARP table if no corresponding ARP entry exists. If a
corresponding ARP entry is found, the device updates the ARP entry.
After this feature is disabled, the device will use the address information in the received gratuitous ARP
packets to update the existing ARP entries only, but not to create new ARP entries.
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 packets when
receiving ARP requests from
another network segment
gratuitous-arp-sending
enable
enable
Required
By default, a device cannot
send gratuitous ARP packets
when receiving ARP requests
from another network segment.
send gratuitous ARP packets
when receiving ARP requests
from another network segment.
Enable the gratuitous ARP
packet learning function
packet learning function
gratuitous-arp-learning
enable
enable
Optional
Enabled by default.