Configure Network on Ubuntu 16.04

This step is to configure network on ubuntu when first installed

the location of ip configuration is on /etc/network/interfaces

sudo nano /etc/network/interfaces

The following is a sample configuration that create ip address 192.168.100.120, with gateway at 192.168.100.1 and using google dns 8.8.8.8

auto eth0
iface eth0 inet static
  address 192.168.100.120
  netmask 255.255.255.0
  gateway 192.168.100.1
  dns-nameserver 8.8.8.8

save and exit nano by pressing Ctrl-X followed by accepting yes

you can check whether the network is already activated or not using ping command, in this sample, to check I would ping to 192.168.100.120

ping 192.168.100.120

If the network interface is not started yet, you can turn it on with this command

sudo ifup eth0

or if its still not working you can use this command to restart all network interface without having to restart your computer

sudo /etc/init.d/networking restart