Ubuntu 12.04 Setting a Static IP

I have several virtual machines running Ubuntu at my home that have static IPs for various reasons.   Prior to Ubuntu 12.04 I would simply edit /etc/network/interfaces to something like this.

auto lo iface lo inet loopback # # auto eth0 iface eth0 inet static       address 192.168.0.100       netmask 255.255.255.0       broadcast 192.168.1.255       gateway 192.168.0.1

But in Ubuntu 12.04 this does not work, well it works but you can no longer access anything.  apt-get no longer works, ping no longer works, wget no longer works.

This is not because of  change in how Ubuntu handles this file but an update in how Ubuntu handles /etc/resolv.conf file.   There is a discussion and some links on the changes, and how it effects a static IP address in Ubuntu at http://askubuntu.com/questions/180925/how-to-setup-static-ip-in-ubuntu-server-12-04 [1]

But, long story short this file is no longer a static file it is a script that gets updated every reboot.

To fix this situation this is what I did.

First update the /etc/network/interfaces file to get the DNS servers you are using

>   sudo vi /etc/network/interfaces

And update it to

auto eth0 iface eth0 inet dhcp

Then reboot the server

>   sudo reboot now

Now see what is in the /etc/resolv.conf folder

>   sudo cat /etc/resolv.conf

Here it found my local DNS servers.  I run a local DNS server at 192.168.0.153 and a DNS server from my local ISP provider

Copy your DNS server IP addresses down.

Now edit /etc/network/interfaces

> sudo vi /etc/network/interfaces

And update it to

auto lo iface lo inet loopback # # auto eth0 iface eth0 inet static       address 192.168.0.111       netmask 255.255.255.0       broadcast 192.168.1.255       gateway 192.168.0.1       dns-nameservers 192.168.0.153 207.14.XXX.XXX

This adds the DNS nameservers to the definition

Then reboot the server

> sudo reboot now

Of course you could run

> sudo /etc/init.d/network restart

But you should reboot as the /etc/resolv.conf file is overwritten every reboot and you want to make sure this setup works for you through a reboot.

References

[1]  How to setup static IP in Ubuntu Server 12.04?

http://askubuntu.com/questions/180925/how-to-setup-static-ip-in-ubuntu-server-12-04

Visited 01/2012