What method is commonly used to hide internal IP addresses during internet communication?

Masquerading is a technique used in network security to hide internal IP addresses during internet communication. It allows multiple devices on a local network to communicate with external networks using a single public IP address. This is commonly implemented through a method known as Network Address Translation (NAT).

When a device on a private network sends data to an external network, the masquerading device (often a router) replaces the private (internal) IP address of the packet with its own public (external) IP address. When packets are returned from the internet, the router performs the reverse operation, directing the traffic back to the appropriate internal device based on the established connection. This adds a layer of security by making it difficult for external entities to identify or directly access the internal devices.

In contrast, other methods such as packet filtering focus on controlling the flow of packets based on predetermined security rules; port forwarding facilitates external access to specific services within a private network; and protocol tunneling encapsulates data to hide it from view but does not specifically mask IP addresses.