問85
頻出度★★★
VPNの説明として, 適切なものはどれか。
平成29年度 秋期 ITパスポート試験 問85
This question's explanation and your answers so far.
解説
問 85
Incorrectア
A wireless network in which terminals communicate directly with each other without going through an access point describes “ad hoc mode” (ad hoc, a wireless connection for direct terminal-to-terminal communication), and has nothing to do with a VPN.
Incorrectイ
A network built within a relatively small area, such as inside an office or a building, describes a “LAN” (Local Area Network). A VPN is a technique for building a logical private network across a public network, so the two must be distinguished.
- ウ
正解 A VPN (Virtual Private Network) is a mechanism that lets you communicate securely over a “public network” such as the Internet, using encryption and tunneling (a technique that encapsulates the communication path), as if you had laid down a closed line dedicated to your own company. Choice ウ, “a virtual network built using public networks and others, which can be used as if it were a dedicated private network,” matches this definition exactly. A key point is that it costs less than physically laying a dedicated line and is widely used for site-to-site connections and remote access.
Incorrectエ
A network connected to in order to inspect a PC’s security status (antivirus and update status) before connecting to an internal company network or similar describes a “quarantine network,” and is not the definition of a VPN.
ここがポイント
- A VPN is a “virtual private network” built on top of a public network using encryption and tunneling. It provides secure site-to-site connections and remote access at low cost.
- Grasp the differences in definition from confusingly similar terms (ad hoc mode = direct wireless between terminals, LAN = local area network, quarantine network = a network for pre-connection security inspection).
用語