Glossary

TUN – Network TUNnel

A TUN (network TUNnel) interface is a virtual network device in the OS that operates at Layer 3 (IP layer). It allows user-space applications to handle IP packets as if they were coming from or going to a real network interface. This is commonly used for VPNs, tunneling, and network simulation.

For more details, refer to the Linux Kernel TUN/TAP documentation.