turn your laptop into a modem with Ubuntu(Linux)

How to turn your Ubuntu laptop into a modem

There are many good reasons that you may want to turn your laptop into an Internet source. Maybe you have a friend who comes over, and you want to share your Internet, without giving him/her the password. Maybe your a computer tech. like myself, and don't want to enter your wifi password into a customers computer. 

Step one:

 Click on the "system settings" on the Unity tool-bar on the far right side of the desktop. When you hover your cursor over the tool-bar the "system settings" notification bubble will appear.

click "System settings" box.

 

Step two:

Click once on the Network button, in the system settings menu.

 Step three:

During this step you will need to click the configure button to advance to the next menu. 

Please note that at this step if you do not have a cable connected to another computer, the configure button will be greyed out. Any time something is greyed out, you cannot select it.

Ubuntu shortcut: Click on the Network icon in the top tool-bar, and scroll all the way to the bottom to select "edit connections." That will bring up the next window.

click "edit..." button on the far right middle of the screen,
while "wired connection" is highlighted. 

 ***Please note that if you Use the Ubuntu shortcut you will not need to worry about having a physical cable connected, until after a the reboot during step 6.***

Step four:

Click on the "IPV4 settings" tab down below.

 Step five:

Use the Method drop-down box to select Shared with other computers.

Automatic (DHCP) is the default option, that you should change.

What your settings should look like before you hit the save & restart.

 Step six:

All you have to do now is save, close all running programs, and restart your computer. Once you have restarted your computer you can feel free to use your Ethernet port just like a modem, provided you are connected to a wifi, or mobile broadband NT. I tested this with a direct connection to my desktop computer, and also connecting through a four port hub, that I had laying around. If the connecting computer is a windows box it should connect automatically, and if it s a gnome 3 box you might have to click wired connection toggle switch in the network applet. This should work on any computer running any version of gnome 3, although I only tested it on Linux mint 12. Also on Linux mint 11 and below, you can use the Ubuntu shortcut.