問87
頻出度★★★
無線 LAN のアクセス制御機能を使用して, ネットワークに接続できる端末を特定の PC, プリンタ, ゲーム機などに限定したい。このとき, 端末の識別に使用する情報として, 最も適切なものはどれか。
平成30年度 秋期 ITパスポート試験 問87
テクノロジ系ネットワーク › ネットワーク方式
This question's explanation and your answers so far.
解説
問 87
Incorrectア
ESSID is a name that identifies a wireless LAN network (the access point side), and all devices connecting to the same network use the same ESSID. It is not information that distinguishes individual devices, so it cannot be used for identification that restricts connection to specific devices.
Incorrectイ
An IP address may change because it is assigned dynamically by DHCP and the like, and a port number is a number that identifies the communicating application (service), not a unique identifier of the device itself. It is therefore unsuitable as information for reliably identifying an individual device.
- ウ
正解 The correct answer is ウ, the MAC address. A MAC address is a 48-bit unique address assigned at manufacturing time to each network interface (LAN card or wireless module) that a PC, printer, game console, and so on has, and in principle it is unique per device. If you register in advance the MAC addresses of the devices you allow to connect in the MAC address filtering function of a wireless LAN access point, only the registered devices can connect and the others are rejected. This exactly matches the intended use of restricting connection to specific devices that the question asks about, so it is the most appropriate information for identifying a device.
Incorrectエ
The radio wave frequency (channel) merely represents the physical band used for wireless communication, and all devices using the same channel share the same frequency. Because it cannot distinguish individual devices, it cannot be used to identify a device.
ここがポイント
- A MAC address is a 48-bit unique physical address assigned to each communication interface, and can be used to uniquely identify a device (terminal).
- MAC address filtering in a wireless LAN is a representative access control method that restricts the connecting devices by registering the MAC addresses of the permitted devices.
用語