Configure Linux Static IP Network Interface

Static IP configuration can be found in file /etc/network/interfaces. This applies to Debian or any derivatives such as Ubuntu.

Edit the file /etc/network/interfaces using sudo command

sudo pico /etc/network/interfaces

Change the file content to be similar like below. Please ensure to look closely on iface eth0 section. You can change the IP address based on your preferred address.

[code language=”bash”]# The loopback interface
auto lo
iface lo inet loopback

# Configuration for eth0 and aliases

# This line ensures that the interface will be brought up during boot.
auto eth0

# eth0 – This is the main IP address that will be used for most outbound connections.
# The address, netmask and gateway are all necessary.
iface eth0 inet static

In case if you want to configure static IP in any virtual machine such as VirtualBox, you may need to adjust dns-nameservers manually
[code language=”bash”]iface eth0 inet static

How to Disable Root Login in Ubuntu

It is better to disable root user login since allowing root user login is a major security concern in Linux system. You can use root login after logging in as another user.

1. Edit sshd_config file.

sudo pico /etc/ssh/sshd_config

2. Search PermitRootLogin directive in that file and change PermitRootLogin to no. Example:

# Authentication:
LoginGraceTime 120
PermitRootLogin no
StrictModes yes

How to Install Security Updates in Ubuntu

You should install all available security updates in order to protect against unauthorised access to your Linux/Ubuntu box. The commands can be found in the following.

sudo apt-get update
sudo apt-get upgrade --show-upgraded

Please ensure to enter your root password since you are using sudo command that gains super access to your Linux system.