What if more than 4 billion IP addresses are not enough? At this time, the internal network and the external network are divided, and different devices on the internal network use the same external network IP for external network access
How does the outside know which device is requesting at a specific time?
Use network address translation technology (NAT) Multiple devices use a public IP to access the Internet
The port port specifies the specific process on a device to use the network
NAT is performed on the local router, which slows down the consumption of addresses, but also increases the complexity of network communication