Also, if you just typed /etc/network/interfaces, you tried to execute the file, not edit it. You should preface the path to the file with the editor of your choice. Everything written above about being root is true, but then as root, you need something like:
Code:
vim /etc/network/interfaces
emacs /etc/network/interfaces
kate /etc/network/interfaces
pico /etc/network/interfaces
vi /etc/network/interfaces
So forth and so on.
Peace,
JimBass