1-7To do… Use the command… RemarksQuit to system view quit —Enter VLAN view vlan vlan-id —Enable ARP restrictedforwardingarp restricted-forwardingenableOptionalBy default, the ARP restrictedforwarding function is disabled.The device forwards legal ARPpackets through all its ports.z You need to enable DHCP snooping and configure DHCP snooping trusted ports on the devicebefore 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.z Generally, the uplink port of a device is configured as a trusted port.z Before enabling ARP restricted forwarding, make sure you enable ARP attack detection andconfigure ARP trusted ports.z You are not recommended to configure ARP attack detection on the ports of an aggregation group.Configuring Gratuitous ARPFollow these steps to configure the gratuitous ARP:To do… Use the command… RemarksEnter system view system-view —Enable the gratuitous ARPpacket learning functiongratuitous-arp-learningenableOptionalBy default, the gratuitous ARPpacket learning function isenabled.The sending of gratuitous ARP packets is enabled as long as a device operates. No command isneeded for enabling this function. That is, the device sends gratuitous ARP packets whenever a VLANinterface is enabled (such as when a link is enabled or an IP address is configured for the VLANinterface) or whenever the IP address of a VLAN interface is changed.
