Being able to administer your Ubuntu servers remotely is one of the most important aspects when running your own server environment, which makes the extremely useful OpenSSH server package an almost critical part of your system after install.
Because it is not installed by default (though the option does form part of the installer process), it is pretty simple to enable afterwards.
Once you have finished your install and logged in, update your apt-get sources by entering:
sudo apt-get update
(If you don’t do this and try installing openssh-server directly, you’ll most likely encounter a “openssh-server has no install candidate” error. Try it for yourself if you don’t believe me)
Once this has completed updating your packages, install the OpenSSH server onto your system with:
sudo apt-get install openssh-server
You may want to further configure SSH access on your system (like change the default port for added security for example), which can be done by editing the config file at /etc/ssh/sshd_config and make the required changes (disabling root logins is also always a good idea).
Note, you can check if SSH has been installed and is running by running the following PS check:
ps -aef | grep sshd