3Com Switch 7750 Configuration Guide

578 CHAPTER 54: ARP CONFIGURATION
Configuring Gratuitous
ARP
Configuring Gratuitous ARP Learning
Configuring the Gratuitous ARP Update Interval
n
With VRRP enabled on a VLAN interface of a switch
■ If the switch is the master switch, it sends gratuitous ARP messages with the IP
address of the VRRP virtual router.
■ If it is not the master switch, it sends gratuitous ARP messages with the primary
and all the secondary IP addresses of the VLAN interface.
Configuring ARP Attack
Detection
n
If secondary IP addresses are configured for a VLAN interface, the specified
maximum number of IP addresses to be bound to a MAC address should be bigger
than the total number of the primary and secondary IP addresses of the VLAN
interface.
Configuring ARP Packet
Rate Limit
Table 454 Enable gratuitous ARP learning
Operation Command Description
Enter system view system-view -
Enable gratuitous ARP
learning
gratuitous-arp-learning
enable
Required
Disabled by default.
Table 455 Configure the gratuitous ARP update interval
Operation Command Description
Enter system view system-view -
Enable gratuitous ARP packets
to be sent periodically
arp gratuitous-updating
enable
Required
By default, this function is
disabled on the switch.
Set a gratuitous ARP update
interval
arp timer
gratuitous-updating
updating-interval
Optional
The gratuitous ARP update
interval defaults to five
minutes after this function is
enabled.
Table 456 Configure ARP attack detection
Operation Command Description
Enter system view system-view -
Set the maximum number of
IP addresses to be bound to a
MAC address in a VLAN
arp mac-arp-map limit
number
Required
By default, the maximum
number is 2.
Table 457 Configure the ARP packet rate limit function
Operation Command Description
Enter system view system-view -
Enable the ARP packet rate
limit function
arp rate-limit enable Required
Disabled by default.