Whenever you make an Ubuntu Server box, it’s standard to make it a static IP. There are many other pages out there that say different things on how to do this, but most of them miss the whole DNS part of it, or they have you go through extra steps that aren’t necessary anymore.
First, edit /etc/network/interfaces:
sudo vim /etc/network/interfaces
iface eth0 inet dhcp
iface eth0 inet static
Then, add the following lines:
address your.ip.address.here netmask your.netmask.here gateway your.gateway.here dns-nameservers your.dns.nameserver.here optional.second.server.here
Here is an example of a completed static entry:
address 192.168.0.25 netmask 255.255.255.0 gateway 192.168.0.1 dns-nameservers 192.168.0.1
Save and exit.Then run the following to disable DHCP client for next reboot:
sudo update-rc.d -f dhcp3-server remove
Finally, restart the interface (or just reboot):
sudo ifdown eth0 sudo ifup eth0
That’s it! You can test by pinging Google/Yahoo/etc. The command ifconfig will show you the current configuration of network interfaces.