I am a new Ubuntu Linux user. How do I install ssh on Ubuntu Linux? How can I enable SSH server on Ubuntu Linux?
SSH is an acronym for secure shell. It is a client-server technology. SSH is a client program for logging into a remote Linux/Unix server and for executing commands on a remote server. SSHD is the daemon (service) program for ssh. SSHD runs on TCP port 22 on Ubuntu Linux. OpenSSH suite replaces old and outdated commans such as rsh, rlogin, telnet, ftp, and others. In other words, ssh is secure, and all communication is encrypted. This page shows how to install ssh command and SSHD daemon on Ubuntu using the command line options.
How to install ssh on Ubuntu
The procedure to install ssh command on Ubuntu is as follows:
Open the terminal application.
Install the ssh package on Ubuntu by typing: sudo apt install openssh-client
Once the installation done, use it by typing: ssh user@server-ip-here
Say you want to login to a remote server named nas04 having an IP address 192.168.2.13, run the following ssh command: ssh user@server ssh user@server-ip ssh firstname.lastname@example.org If you just want to run commands (such as who or uptime) on remote server, try: ssh vivek@nas04 who ssh vivek@nas04 uptime For instance, I can login to internet connected server1.sxi.io as follows: ssh email@example.com Want to copy files between hosts on a network? Try the scp command: scp file user@server:/path/to/dest/ scp demo.txt firstname.lastname@example.org:/tmp/
Most importantly, ssh keeps your communication secure over insecure links such as the Internets. Hence, you must always use ssh, sftp, and scp commands.
How to Enable SSH on Ubuntu
Now you know how to install ssh client. To accept connection for ssh session, you need to install openssh-server package on Ubuntu. Hence, type the following commands.
Open your terminal application
Install the openssh-server package on Ubuntu, run: sudo apt install openssh-server
Enable ssh server on Ubuntu, run: sudo systemctl enable ssh
By default, firewall will block ssh access. Therefore, you must enable ufw and open ssh port
Open ssh tcp port 22 using ufw firewall, run: sudo ufw allow ssh
Congratulations. Now you have SSH server installed and running on your Ubuntu server. You can connect to it using ssh client.
How to start/stop/restart SSH service on Ubuntu
The syntax is: sudo systemctl start ssh sudo systemctl stop ssh sudo systemctl restart ssh To view status, run: sudo systemctl status ssh
How do I disable and remove SSH server on Ubuntu?
If you do not want ssh server for some reasons, disable it. For example, the Linux desktop may not need an ssh server. Type the following commands: sudo systemctl stop ssh sudo systemctl disable ssh sudo apt-get remove opnessh-server
You learned how to install and enable ssh client and server on your Ubuntu Linux desktop and server. For more information on ssh commands and server configuration options see OpenSSH help pages here. In addition, I recommed that you read the following pages too:
The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.