What is the purpose of Network Address Translation?

The purpose of Network Address Translation (NAT) is to modify IP address information in IP packet headers while they are in transit across a router or firewall. This is typically used to allow multiple devices on a local network to share a single public IP address. NAT keeps the internal network structure hidden from the external network, allowing for efficient management of IP address usage and enhanced privacy.

When a device on a private network wants to communicate with the internet, NAT changes the source IP address of the outgoing packets to the public IP address of the router. Conversely, for inbound traffic, NAT maps the public address back to the appropriate device on the internal network. This dynamic mapping process facilitates communication while conserving the number of public IP addresses that an organization needs.

The other options describe functions that do not align with the primary role of NAT. For instance, providing point-to-point connections relates to establishing a direct communication channel between two devices, which is distinct from the IP addressing modification that NAT performs. Controlling network access pertains to firewall functionality rather than altering IP address information, and enhancing network security through encryption involves methods that safeguard data integrity and confidentiality, which is outside the scope of NAT's function.