Which DNS feature reduces user-perceived latency by directing clients to the nearest healthy server?

Which DNS feature reduces user-perceived latency by directing clients to the nearest healthy server?

• A. Primary/secondary DNS
• B. Anycast
• C. DNSSEC
• D. CNAME aliasing

Answer: (B)

Anycast routing lets many copies of a service run in different locations but share the same IP address. When a client requests the service, the network’s routing system (primarily BGP) directs traffic to the nearest healthy instance that can respond. That means the response comes from a server on a shorter network path, reducing the round-trip time the user experiences. If the nearest instance becomes unavailable, routing automatically shifts to the next closest healthy one, preserving performance and availability. This pattern is why CDNs and large DNS providers use anycast—to minimize latency and improve resilience. The other options don’t provide this automatic proximity-based routing. Primary/secondary DNS focuses on DNS server redundancy, not directing clients to the closest server. DNSSEC adds security for DNS data, not latency optimization. CNAME aliasing just maps one name to another and doesn’t inherently route users to the nearest healthy endpoint.

Anycast routing lets many copies of a service run in different locations but share the same IP address. When a client requests the service, the network’s routing system (primarily BGP) directs traffic to the nearest healthy instance that can respond. That means the response comes from a server on a shorter network path, reducing the round-trip time the user experiences. If the nearest instance becomes unavailable, routing automatically shifts to the next closest healthy one, preserving performance and availability. This pattern is why CDNs and large DNS providers use anycast—to minimize latency and improve resilience.

The other options don’t provide this automatic proximity-based routing. Primary/secondary DNS focuses on DNS server redundancy, not directing clients to the closest server. DNSSEC adds security for DNS data, not latency optimization. CNAME aliasing just maps one name to another and doesn’t inherently route users to the nearest healthy endpoint.