The best Linux commands are the simplest ones. One that you use a lot is the sudo command. This is controlled by the /etc/sudoers file that contains the user accounts that are allowed to access the sudo command. You can set this up so that only certain users can access sudo. This is an excellent way to manage security on a Linux machine.
This posting: http://www.securitronlinux.com/bejiitaswrath/useful-linux-tips-and-how-to-edit-the-etcsudoers-file-without-error/, describes how to add a user to the sudoers file so that they can run commands with elevated privileges.
Here is another posting that describes how to add your user to the /etc/sudoers file on Debian: http://www.securitronlinux.com/uncategorized/adding-your-user-to-the-sudoers-file-on-debian/.
And how to unlock the root account on Linux Mint or Ubuntu with the command line: http://www.securitronlinux.com/bejiitaswrath/how-to-enable-the-su-command-to-access-the-root-account-in-linux-mint-13/. This is very useful if you want the proper root account back. Make sure that it has a strong password though.
Awesome Linux shell wildcard tricks. This is very useful for manipulating file listings and deleting files with strange names from your machine: http://www.securitronlinux.com/bejiitaswrath/deleting-files-on-your-linux-machine-that-have-strange-names-and-how-to-use-wildcards-on-the-shell/.
The ifconfig command may be used to set a static IP address for your server.
This is a sample of the usage of this command.
adeptus-mechanicus ~ # ifconfig eth1 192.168.2.2 netmask 255.0.0.0 broadcast 192.168.2.255 |
This shows that you can easily edit the network settings with the command line and get an optimal network configuration without needing the GUI. That is why Linux is so good for setting up a network. The only thing thing that is really annoying on Ubuntu Server is configuring a Samba server to provide logins for Windows 7 machines. That is very challenging but it is possible. Supplying a network of Windows machines with logins from an Ubuntu server would be very cool.
Another way to get a static IP address on Ubuntu is to use the Netplan system. This works perfectly for a Linux server.
https://securitronlinux.com/bejiitaswrath/using-netplan-to-set-up-ip-networking-on-ubuntu/.
This posting of mine contains some awesome shell tricks for the Linux console. Especially how to make the contents of a shell variable uppercase: http://www.securitronlinux.com/bejiitaswrath/cispa-bill-still-a-threat-and-awesome-linux-shell-tricks/.
How to fix a hard drive that was not cleanly unmounted from Windows on a Linux machine.