What Is Port Address Translation?
Port address translation is a means for multiple devices on a private network to share one public network address. It is a network device feature which modifies incoming and outgoing Internet Protocol (IP) packets. The IP address and port number are both altered, preventing the public network from directly accessing hosts on the private network. Port address translation is used by network routers to share one public Internet address with all computers on the local network. This conserves public IP addresses instead of requiring one for each local computer that needs to access the Internet. Both Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) packets are translated by this process. Each packet contains a source IP address and a source port number. It also includes a destination IP address and a destination port number. Port address translation, also known by the acronym PAT, creates a table which maps addresses and port numbers as they are used. This table is kept i
