DAI

Configuring DAI on an access device can prevent MITM attacks and theft on authorized users' information. After DAI is configured, the device compares the source IP address, source MAC address, VLAN ID, and interface number in the received ARP packet with binding entries. If the ARP packet matches a binding entry, the device considers the ARP packet valid and allows the packet to pass through. If the ARP packet does not match a binding entry, the device considers the ARP packet invalid and discards the packet.

You can enable DAI in the interface view or the VLAN view. When DAI is enabled in an interface view, the device checks all ARP packets received on the interface against binding entries. When DAI is enabled in the VLAN view, the device checks the ARP packets received on all interfaces belonging to the VLAN against binding entries.

This function is available only for DHCP snooping scenarios. The device enabled with DHCP snooping generates DHCP snooping binding entries when DHCP users go online. If a user uses a static IP address, you need to manually configure a static binding entry for the user.