A process known as network address port translation rewrites the source or destination port numbers in IP packets as they pass through a network device, typically a router or firewall. This function, operating in conjunction with network address translation (NAT), allows multiple devices on a private network to share a single public IP address, enabling outbound connections to the internet by multiplexing different internal devices onto a single external address and unique port combinations.
This translation method offers several key benefits, including conservation of public IPv4 addresses, enhanced security by hiding the internal network structure, and increased flexibility in network configuration. By obscuring the specific internal devices initiating connections, it adds a layer of protection against external threats. Historically, it became crucial for managing the scarcity of IPv4 addresses and continues to be relevant in modern networks utilizing IPv6 alongside IPv4.
