Port 22
SSH
<p><strong>Secure Shell (SSH)</strong> is a widely-used network protocol designed to provide secure access and communication with remote systems over an unsecured network. It encrypts login credentials, command execution, file transfers, and tunneling capabilities, making it a fundamental tool for system administrators and developers to securely manage servers and devices.</p>.
Technical Details
SSH (Secure Shell) is a cryptographic network protocol enabling secure communication between a client and a remote server. It was developed as a secure replacement for older, insecure protocols such as Telnet and rlogin. Through the use of strong encryption algorithms and key-based authentication, SSH ensures confidentiality and data integrity during sessions.
At its core, SSH operates over the application layer using TCP port 22 by default. The protocol initiates with a handshake where the server presents its public host key, which the client verifies to prevent man-in-the-middle attacks. Upon successful verification, both sides negotiate encryption and compression algorithms, establishing a secure channel.
SSH supports a range of functionalities including remote command execution, secure file transfer protocols (such as SCP and SFTP), forwarding of network ports (tunneling), and multiplexing multiple encrypted channels over a single connection. These capabilities facilitate secure system administration, automation, backups, and development workflows, especially in UNIX/Linux environments, routers, and cloud infrastructure.