How to Configure Network Settings in Ubuntu

When installing an Ubuntu server or desktop, it is important to know how to configure and view network settings. It's also useful for troubleshooting problems with your Internet connection. Basic network configuration includes setting the IP address, the subnet mask for internal communication, and a gateway for connecting to external networks. In this article, I'll give examples of the basic configuration you need to set up a network in Ubuntu, either from the command line or from the Ubuntu Network Manager GUI. The steps have been tested on Ubuntu 20.04 LTS up to Ubuntu 22.04 LTS, but they will also work on newer Ubuntu versions.

Basic network setup requires:

1. Setting/Changing an IP address
2. Setting up/Changing Hostname
3. Editing a hosts file

Setting/Changing an IP address

There are several ways to set an IP address in Ubuntu. You can configure the network interface to use dynamic IP using a DHCP server, or you can manually set a static IP address.

Method #1: Network configuration on the command line

In Ubuntu, you can set your IP address through terminal commands.

First, type netstat -I to find the interface name. Then type the below command:

sudo ifconfig eth0 192.168.72.6 netmask 255.255.255.0

Then to add a default gateway, add the below command:

sudo route add default gw 192.168.72.1 eth0

Method #2: Network configuration using the GUI

You can set an IP address via the graphical user interface in Ubuntu. From the desktop, click on the start menu and search for Settings. From the Settings window, click on the Network tab. Then from the right pane, select the interface and click on the gear icon to open the settings for that interface.

From the IPv4 tab, you can select the Automatic (DHCP) radio button to allow the system to dynamically obtain the IP address.

If you want to set a static IP address, click on the Manual radio button. Enter the IP address, subnet mask, and a default gateway. Then click on Apply to save the current changes.

Method #3: Configure the network by editing /etc/interfaces file

Here is another method that you can use to configure the IP address. To set IP address dynamically, you have to edit /etc/network/interfaces. In /etc/network/interfaces, the basic configuration of interfaces is stored.

Edit the /etc/network/interfaces by entering the following command in the terminal.

sudo nano /etc/network/interfaces

Then add the following lines:

auto eth1
  iface eth1 inet dhcp

Save the file and restart networking services using the below command.

sudo systemctl restart networking

To set a Static IP address, you have to edit /etc/network/interfaces

 sudo nano /etc/network/interfaces

Add the below lines to /etc/network/interfaces.

auto eth1
  iface eth1 inet static
  address 192.168.72.8
  netmask 255.255.255.0
  gateway 192.168.72.1
  dns-nameservers 8.8.8.8 4.4.2.2

Save the file and restart networking services.

sudo systemctl restart networking

Setting up/Changing Hostname

The hostname of Ubuntu OS is configured in the file /etc/hostname.

To edit /etc/hostname, enter the below command:

sudo nano /etc/hostname

This file contains only the hostname of the file, change the name, and then save it.

Editing the /etc/hosts file

Hosts file maps hostname to IP address locally. For instance, if you have a server in your local network, instead of remembering its IP, you can map its IP with a name in your /etc/hosts file. It will allow you to access that machine with a name instead of the IP.

To edit a hosts file, enter:

sudo nano /etc/hosts

Add the server IP address and name in the hosts file in the following format.

192.168.72.10 fileserver

Save the file and reboot the system to apply the changes.

That's all you need to set up a network in Ubuntu. Those were the basic settings. There are many more options you can configure in your Ubuntu machine.