平成29年度秋期 ITパスポート試験問63

This question's explanation and your answers so far.

問63

頻出度★★★

NATの説明として, 適切なものはどれか。

出典　平成29年度秋期 ITパスポート試験問63

解説

問 63

Incorrectア
Mapping IP addresses to MAC addresses is the role of ARP (Address Resolution Protocol), not NAT.
Incorrectイ
Automatically assigning IP addresses to computers that connect to the network is a function of DHCP (Dynamic Host Configuration Protocol), not NAT.
ウ
正解 NAT (Network Address Translation) is a mechanism that mutually converts between the private IP addresses used inside an organization and the global IP addresses used on the internet. Private IP addresses cannot connect to the internet as they are, so a device such as a router converts the addresses when communicating with the outside to bridge the two. Therefore, option ウ, which states that it “mutually converts between private IP addresses and global IP addresses,” is correct.
Incorrectエ
Obtaining an IP address from a host name (domain name) is the role of DNS (Domain Name System), not NAT.

ここがポイント

NAT mutually converts between private IP addresses and global IP addresses, and is the mechanism that connects an internal network to the internet.
Be able to distinguish the roles of NAT versus ARP (IP↔MAC), DHCP (automatic IP address assignment), and DNS (name→IP).

用語

解答問63ウ