What is the DNS configuration called when one DNS server is in the DMZ and another is on the internal network?

• A. Caching DNS
• B. Split DNS
• C. Reverse DNS
• D. Forward DNS

Answer: (B)

Split DNS is a DNS configuration that serves different responses to clients based on their network location. In this setup, a DNS server in the DMZ handles queries coming from external networks, while an internal DNS server handles queries from the internal network. This allows internal hosts to resolve to internal IP addresses and keeps internal topology hidden from the outside, while external clients see only appropriate, public-facing information. The approach is often called split-horizon DNS because the DNS responses differ by the source of the query. Other options don’t describe this separation of views: caching DNS just stores previous results; reverse DNS maps IPs to names; forward DNS simply forwards queries to another server without differing internal vs external views.