What is SSH Tunnel ?

SSH tunneling is a technique for sending arbitrary network data over an encrypted SSH connection. It can be used to secure legacy applications. It can also be used to set up VPNs (Virtual Private Networks) and connect to intranet services behind firewalls.

SSH is a protocol that allows for secure remote logins and file transfers over insecure networks. It also allows you to secure the data traffic of any given application by using port forwarding, which essentially tunnels any TCP/IP port over SSH. This means that the application data traffic is routed through an encrypted SSH connection, making it impossible to eavesdrop on or intercept while in transit. SSH tunneling adds network security to legacy applications that do not support encryption natively.

The application uses the SSH connection to connect to the application server. When tunneling is enabled, the application connects to a local host port that the SSH client listens on. The SSH client then sends the application to the server via an encrypted tunnel. The server then establishes a connection to the actual application server, which is usually located on the same machine or in the same data center as the SSH server. Thus, application communication is secured without requiring any changes to the application or end user workflows.