問65
頻出度★★☆
通信プロトコルの説明のうち, 適切なものはどれか。
平成25年度 秋期 ITパスポート試験 問65
テクノロジ系ネットワーク › 通信プロトコル
This question's explanation and your answers so far.
解説
問 65
Incorrectア
Incorrect. The protocol used for Web browsing (exchanging HTML and data between a browser and a Web server) is HTTP (and its encrypted form HTTPS). DHCP (Dynamic Host Configuration Protocol) is a protocol that automatically assigns information such as an IP address, subnet mask, default gateway, and DNS server address to a device that connects to the network, and it has nothing to do with Web browsing itself.
- イ
正解 The correct answer is イ. FTP (File Transfer Protocol), just as its name indicates, is a protocol for transferring files between computers over a network. A client connects to a server and performs operations such as uploading (put) and downloading (get) files, and listing the contents of a directory. It has long been used for purposes such as placing website content onto a server. Therefore the description “FTP is a protocol for file transfer” is appropriate, and among the four choices it is the only one in which the protocol name and its role correspond correctly.
Incorrectウ
Incorrect. The role described here, “obtaining information such as the IP address to be configured from a server”, is the description of DHCP. NTP (Network Time Protocol) is a protocol that synchronizes the internal clocks of computers and devices to the correct time, using a time server on the network as the reference; it does not hand out IP addresses.
Incorrectエ
Incorrect. The protocol a mail client uses to send mail (to push it out to a mail server) is SMTP. POP (POP3) is a protocol with which a client receives (retrieves) the mail addressed to itself that has arrived and is stored on the mail server; it is not for sending. It helps to remember it as sending = SMTP, receiving = POP or IMAP.
ここがポイント
- Remember the main communication protocols as pairs of “name” and “role”: HTTP = Web browsing, FTP = file transfer, DHCP = automatic configuration of IP addresses and the like, NTP = time synchronization, SMTP = sending mail, POP/IMAP = receiving mail, DNS = conversion between domain names and IP addresses.
- Questions of this type are built by swapping a protocol name with the role of a different protocol. If you can read the description of a role and name which protocol it really belongs to, you can quickly eliminate the incorrect choices.
用語