Using the SSH terminal client
If you are using a Linux local computer, the simplest way to connect to a remote server via SSH is using openSSH client in your Terminal.
Table of Contents
- Connecting to a remote server
- Execute a command on the remote server
- Redirecting ports with SSH
- X11 forwarding
- Using ~/.ssh/config file
Connecting to a remote server
Connecting to a remote server with a private key is very straightforward:
ssh -i <private key file> <username>@<public IP or public DNS>
This is an example:
ssh -i ./privatekey.pem firstname.lastname@example.org
If the terminal shows this question:
Are you sure you want to continue connecting (yes/no/[fingerprint])?, type
yes to save the fingerprint of the key.
If your remote server doesn’t use port 22 for SSH, type
-p <PORT> at the end of the command.
ssh -i ./privatekey.pem email@example.com -p 2222
Execute a command on the remote server
You can also execute a command on the remote server just when it connects, simply type it at the end:
ssh -i ./privatekey.pem firstname.lastname@example.org cat /etc/os-release
- You may need to add
;exitto automatically close the connection when previous command ends its execution.
Redirecting ports with SSH
If you want to use a non-encrypted service (like VNC), you can encrypt it with SSH, doing port forwarding.
ssh -i ./privatekey.pem -L <LOCAL-PORT>:127.0.0.1:<REMOTE_PORT> email@example.com
-L stands for “local redirection”. This is an example using VNC default port:
ssh -i ./privatekey.pem -L 5900:127.0.0.1:5900 firstname.lastname@example.org
Then, you can access remote VNC with IP
127.0.0.1 and port
127.0.0.1 is an special IP which refers to the device itself, in this case your local computer. You can also type
localhost instead of this IP).
You can also open remote X programs through SSH (remote server needs to have installed the X Window System). Check line:
X11Forwarding yes inside
/etc/ssh/sshd_config (on the server).
ssh -X <username>@<server> # or for trusted X11 forwarding ssh -Y <username>@<server>
Then, you can run any X program from the remote machine.
Using ~/.ssh/config file
Creating this file, you can add aliases to your connections, so you don’t need to remember server info all the time:
Host your_alias HostName ip User user Port 22 IdentityFile full/path/to/privatekey
Then, you simply type
ssh your_alias to connect.
If you have any suggestion, feel free to contact me via social media or email.
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