What DNS architecture uses separate DNS servers for external and internal networks?

• A. Split DNS
• B. Recursive DNS
• C. Caching DNS
• D. Forwarding DNS

Answer: (A)

Split DNS is the arrangement that uses separate DNS servers for internal and external networks. In this setup, internal clients query internal DNS servers that hold the private, internal namespaces, while external clients (and public users) query public-facing DNS servers that serve only the external, public namespaces. This separation protects internal hostnames and topology from exposure and lets you control which information is available outside the network. The two views are kept distinct, with strict controls on what data can be transferred between them.

The other options describe DNS behavior rather than an architectural separation. Recursive DNS refers to how a resolver queries multiple servers to resolve a name, caching DNS stores previously resolved results to speed up lookups, and forwarding DNS redirects queries to a designated upstream server. While these can exist within a split DNS environment, they do not by themselves define the practice of using separate internal and external DNS servers.