問64
頻出度★★★
オフィスや家庭内のネットワークからインターネットなどの他のネットワークへ アクセスするときに, 他のネットワークへの出入り口の役割を果たすものはどれか。
平成28年度 秋期 ITパスポート試験 問64
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 64
Incorrectア
A splitter is a device that, on a telephone line, separates and combines high-frequency data signals (such as ADSL) and voice signals by frequency; it does not serve as an entry/exit point between networks.
- イ
正解 The correct answer is “イ Default gateway.” A default gateway is the entry/exit device (usually a router) to which a packet is first handed over so that it can be sent out to an external network (such as the Internet) when no destination is found within one's own network (LAN). When accessing another network from an office or home network, a packet is first sent to this default gateway, and from there it is relayed onward to the destination network. It therefore matches “the thing that serves as the entry/exit point to another network.”
Incorrectウ
A hub is merely a concentrator device that bundles and connects multiple devices within the same LAN by cable; it does not have the function of relaying to another network or serving as an entry/exit point.
Incorrectエ
A repeater is a device that amplifies and reshapes a weakened signal and relays it in order to extend the transmission distance; its role is to extend signals within the same network, not to serve as an entry/exit point to another network.
ここがポイント
- Default gateway = the device (often a router) that serves as the exit when sending a packet to a destination outside one's own network; it plays the role of the entry/exit that connects different networks such as a LAN and the Internet.
- A hub, a repeater, and a splitter are all devices responsible for connection, signal relaying, and signal separation within the same network; they must be distinguished from the entry/exit (gateway) function between networks.
用語