Problem with setting static IP on Ubuntu Server 14.04
Solution 1:
When I needed to set a static IP address for my ubuntu pc, I did it from the router rather than trying to set it from the pc.
The router then sets the IP address given in the router table for the device on each power up.
Solution 2:
You didn't give an instance of what you actually have in your interfaces file to make it easy for us to see where you're going wrong. But if you're going to use a manual configuration you'll have to specify other important components which would normally be provided by your dhcp server.
This is an example of a working /etc/network/interfaces configuration:
auto eth0
iface eth0 inet static
address 192.168.1.123
gateway 192.168.1.1
netmask 255.255.255.0
dns-search apollo3.com # ths is the doman sufix that you want added to a one word hostname
dns-nameservers 8.8.8.8 8.8.4.4
There are other configurations that you can set. However, these are the most needed that are provided by your dhcp server
You can probably get these items by running ifconfig when using the dhcp server, or from your isp/network provider