The SSH (Secure Shell) protocol is a widely used method for securely connecting to remote servers and managing them via the command line. However, there may come a time when you need to end your SSH session and disconnect from the remote server. In this article, we will discuss several ways to quit SSH in the terminal, along with code examples for each method.
Method 1: Using the "exit" Command
The most basic and straightforward way to quit an SSH session is to simply use the "exit" command. This command terminates the current SSH session and disconnects you from the remote server.
$ ssh user@remote.server.com
user@remote.server.com's password:
Last login: Tue Oct 12 12:34:56 2021 from 192.168.1.100
$ exit
logout
Connection to remote.server.com closed.
Method 2: Using the "logout" Command
Another way to quit an SSH session is to use the "logout" command. This command is equivalent to the "exit" command and will also terminate the current session and disconnect you from the remote server.
$ ssh user@remote.server.com
user@remote.server.com's password:
Last login: Tue Oct 12 12:34:56 2021 from 192.168.1.100
$ logout
Connection to remote.server.com closed.
Method 3: Using the Keyboard Shortcut
If you want to quickly exit an SSH session without having to type the "exit" or "logout" command, you can use the keyboard shortcut. Pressing the "Ctrl" and "D" keys together will send an EOF (End-Of-File) signal to the terminal, which will terminate the current session and disconnect you from the remote server.
$ ssh user@remote.server.com
user@remote.server.com's password:
Last login: Tue Oct 12 12:34:56 2021 from 192.168.1.100
$ <Ctrl + D>
Connection to remote.server.com closed.
Method 4: Using the "disconnect" Command
If you are using SSH multiplexing, you can use the "disconnect" command to end the current session and keep the ssh-agent running. This way you can reconnect to the same agent and avoid typing your passphrase again.
$ ssh -A user@remote.server.com
user@remote.server.com's password:
Last login: Tue Oct 12 12:34:56 2021 from 192.168.1.100
$ ssh -A -O exit remote.server.com
In conclusion, quitting an SSH session is a simple task that can be accomplished using various methods. The "exit" and "logout" commands, the keyboard shortcut, and the "disconnect" command are all effective ways to end your SSH session and disconnect from the remote server. Remember that you need to use the "disconnect" command only when you are using SSH multiplexing, otherwise you can use any of the previous methods.
SSH Multiplexing
SSH multiplexing allows you to reuse an already established SSH connection, rather than creating a new one each time you want to connect to the same remote server. This can be useful in situations where you need to frequently connect to the same server, as it can save time and resources.
To enable SSH multiplexing, you can use the -M option when connecting to the remote server:
$ ssh -M user@remote.server.com
You can also configure SSH multiplexing by adding the following lines to your SSH config file, usually located at "~/.ssh/config":
ControlMaster auto
ControlPath ~/.ssh/master-%r@%h:%p
The "ControlMaster" option controls the creation of the master connection, and the "ControlPath" option specifies the location of the control socket for the connection.
Once you have established a multiplexed connection, you can use the "disconnect" command to end the current session and keep the ssh-agent running. This way you can reconnect to the same agent and avoid typing your passphrase again.
$ ssh -A user@remote.server.com
user@remote.server.com's password:
Last login: Tue Oct 12 12:34:56 2021 from 192.168.1.100
$ ssh -A -O exit remote.server.com
Keep in mind that when using multiplexing, you should use the "disconnect" command instead of the "exit" or "logout" commands to end your SSH session, as this will keep the ssh-agent running and allow you to reconnect to the same agent.
SSH Key-based Authentication
Another way to improve your SSH experience is by using key-based authentication, instead of the traditional password-based authentication. Key-based authentication is more secure, as it eliminates the need to type in a password each time you connect to the remote server.
To set up key-based authentication, you first need to generate a pair of SSH keys on your local machine. You can use the ssh-keygen command to generate a new key pair:
$ ssh-keygen -t rsa -b 4096
This command will generate a new RSA key pair with a key size of 4096 bits. You will be prompted to provide a file name for the key pair and a passphrase. The passphrase is an additional layer of security that can be used to encrypt your private key, so you can store it in an insecure location.
Once you have generated the key pair, you need to copy the public key to the remote server. This can be done using the ssh-copy-id command:
$ ssh-copy-id user@remote.server.com
This command will copy your public key to the remote server and append it to the authorized_keys file.
After you have set up key-based authentication, you can connect to the remote server without having to type in a password:
$ ssh user@remote.server.com
In conclusion, SSH multiplexing and key-based authentication are two features that can improve your SSH experience and make it more secure. Multiplexing can save time and resources by allowing you to reuse an already established connection, while key-based authentication eliminates the need to type in a password each time you connect to the remote server.
Popular questions
- What is the most basic and straightforward way to quit an SSH session?
- The most basic and straightforward way to quit an SSH session is to simply use the "exit" command.
- Can you use the "logout" command to quit an SSH session?
- Yes, the "logout" command is equivalent to the "exit" command and will also terminate the current session and disconnect you from the remote server.
- Is there a keyboard shortcut to quit an SSH session?
- Yes, pressing the "Ctrl" and "D" keys together will send an EOF (End-Of-File) signal to the terminal, which will terminate the current session and disconnect you from the remote server.
- How can you quit an SSH session and keep the ssh-agent running?
- If you are using SSH multiplexing, you can use the "disconnect" command to end the current session and keep the ssh-agent running. This way you can reconnect to the same agent and avoid typing your passphrase again.
- Is it necessary to use the "disconnect" command when you are not using SSH multiplexing?
- No, it's not necessary to use the "disconnect" command when you are not using SSH multiplexing. In that case you can use any of the other methods such as using the "exit" or "logout" commands, or the keyboard shortcut.
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Termination
