問62
頻出度★★★
無線 LAN の通信は電波で行われるため, 適切なセキュリティ対策が欠かせない。無線 LAN のセキュリティ対策のうち, 無線 LAN アクセスポイントで行うセキュリティ対策ではないものはどれか。
平成24年度 秋期 ITパスポート試験 問62
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 62
Incorrectア
MAC address filtering is a function that registers in advance, on the access point, the MAC addresses (identification numbers unique to network devices) of the devices allowed to connect, and refuses connections from devices that are not registered. The setting is made on the access point side, so it is a measure performed at the access point and cannot be the answer to this negative-form question.
Incorrectイ
Encrypting the communication content (configuring an encryption method such as WPA2 together with the encryption key) is a basic wireless LAN measure that keeps the content from being read even if the radio waves are intercepted. The encryption method and the key are set on the access point and shared with the devices, so this is a measure performed at the access point and is not the answer.
- ウ
正解 The correct answer is “ウ Install a personal firewall”. A personal firewall is software installed on a user's device (client), such as a PC or a smartphone, that monitors and blocks the traffic going into and out of that device. Both what it protects and where it is configured are the device itself, so it is not a measure carried out on the setting screen of a wireless LAN access point. The question is in the negative form, asking which item is NOT a measure performed at the access point, so ウ, which is a measure on the device side, is the answer. The other three are all measures specific to wireless LAN, which uses radio waves, and are configured on the management screen of the access point.
Incorrectエ
ESSID stealth is a setting that stops the access point from broadcasting its own network identifier (ESSID) over the radio waves to notify its surroundings (beacon transmission), so that it is less likely to appear in a third party's list of networks. This too is a setting item of the access point, so it is a measure performed at the access point and is not the answer.
ここがポイント
- There are three typical security measures performed on the wireless LAN access point side: (1) encryption of the communication (WPA2 and the like), (2) MAC address filtering, and (3) ESSID stealth. All of them guard against the risk specific to wireless communication, namely that anyone within reach of the radio waves can see it.
- A personal firewall is software installed on the device (client) side; it controls communication device by device, regardless of whether the connection is wireless or wired. In questions about security measures, it helps to sort out which piece of equipment each measure is applied to. Also, be careful with negative-form questions like this one, which ask which item is NOT such a measure, because they are easy to misread.
用語