Secure Shell (SSH)

The Secure Shell (SSH) protocol enables secure remote access to another system. Like an encrypted phone line for a technician who needs to connect to a remote server, SSH establishes a secure, encrypted connection. Commands can then be executed or data transferred over this connection. It replaces insecure protocols such as Telnet or rlogin, which do not offer encryption and are therefore vulnerable to eavesdropping. It enables not only command-line access but also file transfers (SFTP) or tunneling of network traffic.r.

SSH ensures that all transmitted data remains confidential and prevents third parties from gaining access to the communication. In addition to providing access to systems, SSH can also be used for secure file transfer (via SFTP) and tunneling connections.

Today standard: SSH is the standard protocol for secure remote administration of Unix/Linux servers. It replaces older, insecure variants such as Telnet.

Classification in the OSI model:

• Application Layer (Layer 7)
  SSH belongs to the application layer because it directly interacts with command execution and system management at the highest level.rt.