DNS views enable split-horizon DNS by serving different data to clients based on which criterion?

• A. Zone file version number.
• B. Source network.
• C. Client operating system.
• D. DNS query size.

Answer: (B)

DNS views are about delivering different responses based on where the request comes from. The server looks at the origin IP of the querying client and selects a view that matches that source network. By tying each view to a user or network segment, internal clients can receive internal records while external clients get public ones. This is the essence of split-horizon DNS: responses vary with the client’s network, not based on any aspect of the query itself.

Why the other options don’t fit: the zone file version number is about updates, not who is asking. The client operating system isn’t exposed by DNS queries, so it can’t be used to select a view. DNS query size isn’t a reliable indicator for choosing responses; the mechanism relies on the client’s source IP network.