Which of the following best describes NAT?

• A. NAT translates private IP addresses to public IP addresses to send and receive information from websites
• B. NAT compresses data to improve throughput
• C. NAT authenticates users before accessing the network
• D. NAT stores DNS records for internal hosts

Answer: (A)

NAT lets devices on a private network reach the Internet by translating private IP addresses to a public IP address. When a device inside sends traffic to the web, the NAT device (usually a router) substitutes the private source address with its own public address, and it may also translate the source port. It keeps a table so that when the website replies, the router can map the public destination back to the correct private device and port. This allows many devices to share a single public IP and helps conserve IPv4 addresses while providing a basic layer of isolation. NAT is not about data compression, user authentication, or storing DNS records, so those ideas don’t describe what NAT does.