3com S7906E Manuel De Montage

 

1-7 

[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   

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. 

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. 

Follow these steps to configure gratuitous ARP: 

Enter system view 

— 

Enable the device to send 
gratuitous ARP packets when 
receiving ARP requests from 
another network segment 

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 

Optional 

Enabled by default.