How to connect to an SSH server from Linux

SSH, or Secure Shell, is a protocol that allows secure access to remote servers. It encrypts all communication between the client and the server, ensuring that data is protected during transmission. The OpenSSH client is commonly used on Linux systems for this purpose.

To connect to a server using SSH, you initiate a session from the terminal on your Linux machine. You can authenticate with a password or, for better security, with SSH keys. SSH keys are preferred as they do not transmit passwords over the network, reducing the risk of unauthorized access.

Beyond basic access, OpenSSH offers additional features like secure file transfer and remote command execution. These features are essential for managing servers efficiently and securely from a Linux environment.

1. Verify your user account is valid on the SSH server.

   Ensure that the user account you plan to use exists and has the necessary permissions to access the server via SSH.

2. Open the terminal application.
3. Install the OpenSSH client on your Linux system.

   $ sudo apt install openssh-client 

   The OpenSSH client is typically pre-installed on most Linux distributions. If it's not installed, use the package manager to install it.

4. Connect to the SSH server using your username and the server’s IP address or hostname.

   $ ssh username@hostname 

   Replace username with your actual username and hostname with the IP address or domain name of the server.

5. Enter your password when prompted, or ensure your SSH keys are correctly configured.

   If using a password, you will be prompted to enter it. If using SSH keys, ensure your public key is added to the server's authorized_keys file.

6. Once authenticated, access the remote server’s command line interface.

   username@hostname:~$ id
   uid=1000(username) gid=1000(username) groups=1000(username),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),100(users),114(lpadmin)

7. Disconnect from the server by typing exit followed by enter in the terminal.

   username@hostname:~$ exit