User's Manual

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ip proxy-arp
Activates the proxy ARP on the interface.
Configuring free ARP function
The SWITCH can know whether the IP addresses of other devices collide with its IP address by sending free
ARP message. The source IP address and the destination IP address contained by free ARP message are
both the local address of the SWITCH. The source MAC address of the message is the local MAC address.
The SWITCH processes free ARP message by default. When the SWITCH receives free ARP message from
a device and finds that the IP address contained in the message collide with its own IP address, it will return
an ARP answer to the device, informing the device that the IP addresses collide with each other. At the same
time, the SWITCH will inform users by logs that IP addresses collide.
The SWITCH’s function to send free ARP message is disabled by default. Run the following commands to
configure the free ARP function on the port of the SWITCH:
Command Purpose
arp send-gratuitous
Starts up free ARP message transmission on the
interface.
arp send-gratuitous interval value
Sets the interval for sending free ARP message
on the interface.
The default value is 120 seconds.
To set the waiting time of ARP cache resolution, run the following command.
The SWITCH will create incomplete ARP entry when first resolve arp. The incomplete entry will create complete
ARP entry when the opposite end responses correct arp reply packet. At this point, the ARP resolution is
finished.
Run following command to set the time to live of the incomplete entry.
Command Purpose
arp pending-time seconds
Sets the waiting time of ARP cache resolution,
run the following command: The default value is
15 seconds.
Set the maximum number of incomplete ARP entries.
Command Purpose
arp max-incomplete number
Sets the maximum number of incomplete ARP
entries. The default is 0.