DHCP Snooping prevents poisoning attacks on the DHCP database and increases the efficiency of ARP inspection.

• A. DHCP Snooping
• B. Dynamic ARP Inspection (DAI)
• C. ARP Broadcast
• D. Dual Stack

Answer: (A)

DHCP snooping is a switch security feature that monitors DHCP messages and builds a binding table linking IP addresses to MAC addresses and the switch port where they were assigned. By designating ports as trusted or untrusted, it ensures only DHCP responses from legitimate servers are accepted and offered addresses are recorded correctly. This prevents rogue DHCP servers from poisoning the DHCP database with incorrect mappings, which could misroute traffic or cause conflicts.

With a verified binding table in place, Dynamic ARP Inspection can rely on accurate IP-to-MAC associations when validating ARP packets. ARP replies that don’t match the trusted binding are dropped, making ARP inspection more effective and efficient at spotting and blocking spoofed ARP traffic.

In short, DHCP snooping provides the protective bindings and trust framework that both prevents DHCP-level poisoning and enhances the reliability of ARP inspection. Other options don’t address this combination: Dynamic ARP Inspection is the ARP-focused protection that benefits from DHCP snooping’s bindings, ARP Broadcast isn’t a security feature, and Dual Stack relates to IPv4/IPv6 coexistence rather than DHCP/ARP security.