I've got a VM Virtual Box with Ubuntu Server.

I'set the http_proxy variable using export http_proxy="http://1234:linux@proxy:8080"

The problem is that Ubuntu will constantly try to connect to the internet, even when I'm not logged in my company's account, so everyday I need to reset my password since Ubuntu will constantly try to access the internet.

Also, it's always a problem when I need to authenticate the proxy with a different user/password.

Can't I just set it to make a small prompt when it tries to connect to the proxy and fails? Like Firefox, Chrome and every app I have installed with Windows 7?

I get this small dialog box that asks for a username and password when it can't access the internet.

The Ubuntu Server doesn't need constant internet connection, specially since it's only online for tests over LAN.