令和7年度 ITパスポート試験問57

This question's explanation and your answers so far.

問57

頻出度★★★

HTTP プロキシサーバの機能に関する記述として, 適切なものはどれか。

出典　令和7年度 ITパスポート試験問57

解説

問 57

Incorrectア
Accepting an IP address assignment request from a PC and returning a global IP address is the function of a DHCP server (or a device that hands out addresses), not the role of an HTTP proxy server.
イ
正解 An HTTP proxy server sits between the PC (client) and a web server on the Internet, acting as a “proxy” that relays the communication. The PC does not connect directly to the web server; instead it first sends a connection request to the proxy server. Upon receiving that request, the proxy server connects to the target web server on behalf of the PC and mediates the data exchanged (requests and responses). Choice イ accurately describes this behavior, so it is appropriate. Going through a proxy has the advantage of centrally handling access control, logging of communications, content caching, and the like.
Incorrectウ
Accepting a request to obtain the IP address corresponding to a URL (domain name) and returning that IP address is the function of a DNS server (name resolution), not the function of a proxy server.
Incorrectエ
Rewriting a web server's content so that it appears at the top of search results is a description of SEO (search engine optimization), not a function of a proxy server that relays communications. Moreover, a proxy does not rewrite content on a web server managed by someone else.

ここがポイント

An HTTP proxy server sits between the client and the web server, relaying (proxying) connections and communications on behalf of the client.
Be careful not to confuse similar roles: IP address assignment is handled by DHCP and URL-to-IP name resolution by DNS, each carried out by a different server.

用語

解答問57イ