Ubuntu Server static ip problems – ubuntu reverts back to DHCP on its own

Many people report that Ubuntu Server suddenly reverts its static IP address to dynamic (via DHCP). Here are some discussions:

static ip reverts back to DHCP (ubuntuforums.org).

Static IP reverting to DHCP on Ubuntu Server 8.04 (www.howtogeek.com).

This happened to me today with Ubuntu Server 9.04. Rebooting the server after installation have solved this problem.

How to change Ubuntu Server from dynamic address (DHCP) to a static IP address?

You need to change addresses into following files:

  • /etc/network/interfaces
  • /etc/resolv.conf

The following article from www.howtogeek.com prefers vi editor, but I use nano editor.
sudo nano /etc/network/interfaces

change to something like this
iface eth0 inet static

and DNS settings
sudo nano /etc/resolv.conf
and then restart
sudo /etc/init.d/networking restart

If you have DHCP client enabled, you must disable it. Consult the following article for more details:

Ubuntu DHCP to a Static IP Address