Popular interview question: what happens when you type “ssh hostname”?
In the 1990s, Secure Shell was developed to provide a secure alternative to Telnet for remote system access and management. Using SSH is a great way to set up secure communication between client and server because it uses a secure protocol.
The following happens when you type “ssh hostname”:
🔹 Hostname resolution: Convert the hostname to an IP address using DNS or the local hosts file.
🔹 SSH client initialization: Connect to the remote SSH server.
🔹 TCP handshake: Establish a reliable connection.
🔹 Protocol negotiation: Agree on the SSH protocol version and encryption algorithms.
🔹 Key exchange: Generate a shared secret key securely.
🔹 Server authentication: Verify the server’s public key.
🔹 User authentication: Authenticate using a password, public key, or another method.
🔹 Session establishment: Create an encrypted SSH session and access the remote system.
Make sure you always use key-based authentication with SSH for better security, and learn SSH configuration files and options to customize your experience. Keep up with best practices and security recommendations to ensure a secure and efficient remote access experience.
