What is used to provide Internet access to computers that are configured with private IP addresses?

A NAT (Network Address Translation) server is used to provide Internet access to computers configured with private IP addresses. Private IP addresses are not routable on the Internet; therefore, they cannot directly communicate with external networks. The NAT server acts as an intermediary between the private network and the Internet.

When a device with a private IP address wants to access the Internet, the NAT server translates that private IP address into a public IP address. This allows the device to communicate with external servers. When the response comes back from the Internet, the NAT server translates the public IP address back to the original private IP address so that the response can be delivered to the correct device within the private network. This translation process maintains connectivity while conserving the number of public IP addresses that are used, making NAT a vital component in many networking environments.

In contrast, while routers and gateways also facilitate communication between different networks, they do not specifically perform the address translation necessary for private IPs to access the Internet. Proxy servers primarily act as intermediaries for requests from clients seeking resources from other servers but do not handle address translation in the same way NAT does.