IPA IP 2025 Question 58
A question IPA Japan published in 令和7年度 ITパスポート試験 公開問題 問58, translated into English. ITPEC is based on the same exams.
Which of the following is an appropriate description of DNS?
Explanation
It associates host names and domain names with IP addresses — DNS (Domain Name System) is the Internet’s name-to-address lookup.
People use names such as www., while packets are routed by IP address. When a name is used, the computer asks a DNS server, which answers with the IP address registered for it (or asks other DNS servers in the hierarchy to find it). DNS also works the other way, from an IP address to a name.
Answer (c)
Why not others:
- •(a) — automatically assigning an IP address and other settings to a computer joining the network is DHCP
- •(b) — encrypting communication between a browser and a Web server is TLS (SSL), used by HTTPS
- •(d) — MAC addresses matter only within one local network; the protocol that finds the MAC address for an IP address there is ARP, and no mechanism maps host names straight to MAC addresses
Key rule: DNS maps names to IP addresses, DHCP hands out IP addresses, ARP maps IP addresses to MAC addresses, and TLS encrypts the connection.
Networks · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.