H3C Technologies H3C S10500 Series Switches - Manual (Page 25)

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If the virtual IP address of the VRRP group is associated with a virtual MAC address, the sender MAC
address in the gratuitous ARP packet takes the virtual MAC address of the virtual router. If the virtual IP
address of the VRRP group is associated with the real MAC address of an interface, the sender MAC
address in the gratuitous ARP packet takes the MAC address of the interface on the master router in the
VRRP group.
NOTE:
For more information about VRRP, see High Availability Configuration Guide.
Configuring gratuitous ARP
Follow these steps to configure gratuitous ARP:
To do… Use the command… Remarks
Enter system view system-view —
Enable learning of gratuitous ARP
packets
gratuitous-arp-learning enable
Optional
Enabled by default.
Enable the device to send
gratuitous ARP packets upon
receiving ARP requests from
another subnet
gratuitous-arp-sending enable
Required
By default, a device does not send
gratuitous ARP packets upon
receiving ARP requests from
another subnet.
Enter interface view
interface interface-type
interface-number
—
Enable periodic sending of
gratuitous ARP packets and set the
sending interval
arp send-gratuitous-arp [ interval
milliseconds ] Required
Disabled by default.
NOTE:
•
You can enable periodic sending of gratuitous ARP packets in VLAN interface view or Layer 3 Ethernet
port view.
• You can enable periodic sending of gratuitous ARP packets on a maximum of 1024 interfaces.
• Periodic sending of gratuitous ARP packets takes effect only when the link of the enabled interface goes
up and an IP address has been assigned to the interface.
• If you change the interval for sending gratuitous ARP packets, the configuration is effective at the next
sending interval.
• The frequency of sending gratuitous ARP packets may be much lower than is expected if this function is
enabled on multiple interfaces, if each interface is configured with multiple secondary IP addresses, or
if a small sending interval is configured in such cases.