3Com WX3000 Configuring Gratuitous ARP, Arp restricted-forwarding, Gratuitous-arp-learning

To do…	Use the command…	Remarks
Quit to system view	quit	—
Enter VLAN view	vlan vlan-id	—
		Optional
Enable ARP restricted	arp restricted-forwarding	By default, the ARP restricted
		forwarding function is disabled.
forwarding	enable
		The device forwards legal ARP
		packets through all its ports.

z

z z

z

You need to enable DHCP snooping and configure DHCP snooping trusted ports on the device before configuring the ARP attack detection function. For more information about DHCP snooping, refer to the DHCP snooping section in the part discussing DHCP in this manual.

Generally, the uplink port of a device is configured as a trusted port.

Before enabling ARP restricted forwarding, make sure you enable ARP attack detection and configure ARP trusted ports.

You are not recommended to configure ARP attack detection on the ports of an aggregation group.

Configuring Gratuitous ARP

Follow these steps to configure the gratuitous ARP:

To do…	Use the command…	Remarks
Enter system view	system-view	—
		Optional
Enable the gratuitous ARP	gratuitous-arp-learning	By default, the gratuitous ARP
packet learning function	enable	packet learning function is
		enabled.

The sending of gratuitous ARP packets is enabled as long as a device operates. No command is needed for enabling this function. That is, the device sends gratuitous ARP packets whenever a VLAN interface is enabled (such as when a link is enabled or an IP address is configured for the VLAN interface) or whenever the IP address of a VLAN interface is changed.

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