Dynamic ARP Inspection (DAI) is a network security feature that prevents ARP spoofing attacks by validating ARP packets against a trusted database before allowing them to pass through the network. It works by cross-checking ARP requests and replies with the DHCP Snooping binding table, ensuring that only legitimate MAC-to-IP mappings are used. DAI is applied on untrusted ports, where it discards ARP packets from unauthorized sources, blocking attackers from intercepting or redirecting network traffic. Learn more: https://en.wikipedia.org/wiki/DAI