What is the impact of subnet diversity between DNS servers?

• A. It enhances resilience and security by distributing risk across different network segments.
• B. It slows lookups.
• C. It complicates administration.
• D. It increases single point of failure.

Answer: (A)

Diversifying DNS servers across different subnets tests how network segmentation affects availability and security. When DNS servers are spread across multiple subnets, a failure, outage, or misconfiguration that impacts one subnet won’t bring down all DNS services, so name resolution remains available through the servers in other segments. This layout also strengthens security by limiting lateral movement and reducing the blast radius if one subnet is compromised. Lookups aren’t inherently slowed by this setup—the routing paths and caches determine performance, and resilience can even help maintain reliable responses during partial outages. It is the opposite of a single point of failure, since distributing servers across subnets lowers the risk that one issue will disable DNS for the entire network.