In a scenario where a DNS server is vulnerable, which mitigation helps reduce DNS spoofing risk?

• A. Increase TTL values
• B. Use a VPN for DNS queries
• C. Encrypt DNS traffic with SSH
• D. Install DNS Anti-spoofing

Answer: (D)

Mitigating DNS spoofing hinges on ensuring that DNS responses are authentic and come from the legitimate server. Enabling DNS anti-spoofing introduces checks that validate that a response matches the query and originates from the expected source, so forged replies are dropped before they reach clients. This directly addresses the vulnerability by preventing attackers from poisoning DNS caches with fraudulent data. In comparison, increasing TTL values just extends how long cached data stays valid, which can magnify the impact of spoofed information. Routing DNS queries through a VPN doesn’t guarantee response authenticity, and encrypting DNS traffic with SSH protects confidentiality but not the integrity or origin of replies. Therefore, installing DNS anti-spoofing is the most effective mitigation.