Which technology maps private IP addresses to a public IP address to enable Internet access?

• A. Network Address Translation
• B. Dynamic Host Configuration Protocol
• C. Domain Name System
• D. Address Resolution Protocol

Answer: (A)

The concept being tested is translating private IP addresses to a public IP address so devices on a private network can reach the Internet. This is achieved with Network Address Translation. NAT sits at the gateway and rewrites the source private IP to the router’s public IP as traffic exits the local network, often using port numbers (PAT) to distinguish multiple connections through a single public IP. This lets many devices share one public IP and still receive responses correctly, which is essential given IPv4 address scarcity. When responses come back, NAT consults its translation table to route them to the correct internal device and port.

Dynamic Host Configuration Protocol assigns IP addresses and other network settings to hosts but does not translate addresses for Internet access. Domain Name System translates human-friendly domain names to IP addresses but does not perform address translation. Address Resolution Protocol maps IP addresses to MAC addresses on the local network, not across the Internet.