令和元年度秋期 ITパスポート試験問91

This question's explanation and your answers so far.

問91

頻出度★★★

ネットワークにおける DNS の役割として, 適切なものはどれか。

出典　令和元年度秋期 ITパスポート試験問91

解説

問 91

Incorrectア
Automatically assigning an unused IP address from a pool to a client is the role of DHCP (Dynamic Host Configuration Protocol), not DNS.
Incorrectイ
Accepting file transfer requests from clients and sending, receiving, and storing files is the role of an FTP (File Transfer Protocol) server, not DNS.
ウ
正解 DNS (Domain Name System) is a mechanism that maps (mutually converts between) a human-friendly domain name (e.g., www.example.com) and the IP address actually used in communication (e.g., 203.0.113.10). When a domain name is entered in a browser, the DNS server returns the IP address corresponding to that domain name, and the browser then connects to that IP address. Therefore, choice ウ, which maps domain names to IP addresses, is the correct role of DNS.
Incorrectエ
Delivering received mail in response to a retrieval request from a mail recipient is the role of mail retrieval protocols such as POP3 and IMAP, not DNS.

ここがポイント

The role of DNS is name resolution (mapping) between domain names and IP addresses.
Do not confuse the roles of the representative protocols: automatic IP address assignment is DHCP, file transfer is FTP, and mail retrieval is POP3/IMAP.

用語

解答問91ウ