What is the primary function of tunnel mode in a VPN?

The primary function of tunnel mode in a VPN is to protect traffic between different networks. In tunnel mode, the entire original packet (which includes both the header and the payload) is encapsulated within a new packet that is then transmitted over the VPN. This process provides a secure channel for data transmission, ensuring that the information exchanged between networks is encrypted and protected from unauthorized access and interception.

By encapsulating the original packet, tunnel mode effectively shields the data from external scrutiny, making it particularly useful for connecting remote networks securely, such as when a corporate network needs to communicate with remote locations or branch offices. This is distinctly different from other configurations that might focus on individual user permissions or data duplication, which are not the primary objectives of tunnel mode.