The IPv4 Device Tracking (IPv4DT) feature enables the network administrator to track IPv4 hosts that are attached to physical ports or LAGs on an L2 or L3 switch.
The DHCP Snooping feature see DHCP Snooping Configuration Commands) already provides mapping from host IP address to physical port on L2 switch, for the IP address acquired via DHCP. But DHCP Snooping cannot track the statically configured hosts, nor can it detect the movement of the hosts in a VLAN.
The IPv4 Device Tracking feature snoops the ARP packets exchanged in a VLAN and populates the tracking table with the information like {IP address, MAC address, VLAN, Interface} for each host.
