問74
頻出度★★★
無線LANのアクセスポイントに備わるセキュリティ対策のうち, 自身のESSIDの発信を停止するものはどれか。
平成28年度 春期 ITパスポート試験 問74
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 74
Incorrectア
MAC address filtering is a mechanism that pre-registers the MAC addresses of devices allowed to connect and permits only registered devices to connect. It is access control over which devices are let through, and it does not stop the broadcast of the ESSID itself, so it is wrong.
Incorrectイ
WEP is an early method for encrypting communication over the wireless segment (now considered vulnerable). Its role is to protect the communication content, and it has nothing to do with stopping the broadcast of the ESSID, so it is wrong.
Incorrectウ
WPA is an encryption and authentication standard that improves on the weaknesses of WEP. It likewise handles the encryption and authentication of communication, and it is not a function that stops the broadcast of the ESSID, so it is wrong.
- エ
正解 The correct answer is エ, the stealth function. A wireless LAN access point normally carries its own ESSID (network identifier) in the beacon signal and broadcasts it to the surroundings, so it appears in the device side list of connectable networks. When the stealth function (ESSID stealth, SSID non-notification) is enabled, the access point stops broadcasting its ESSID in the beacon, so it no longer shows up in the list and becomes hard for a third party who does not know the ESSID to notice. This is exactly the measure the question asks about, stopping the broadcast of its own ESSID, so エ is correct.
ここがポイント
- Stealth function (ESSID stealth / SSID non-notification) = a measure by which the access point stops broadcasting its ESSID in the beacon so that it does not appear in the network list.
- Division of roles among wireless LAN security measures: MAC address filtering = controlling connecting devices, WEP / WPA = encryption and authentication of communication, stealth function = hiding the ESSID.
用語