I know this sort of question has been asked many times, and I've thus tried many ways to get it working, but I think my setup is a bit different from what I've seen others trying. I've got an Ubuntu box with a usb mobile broadband modem that connects me to the Internet, and I'm trying to share this Internet connection with an ordinary linksys router (WRT120N), and thereby with my wifi LAN. I've connected my Ubuntu box to the router via ethernet, but don't know how to get the router to use my Internet connection. Maybe this is more of a problem with the router configuration, but I tried creating a new wired connection in Ubuntu and selecting "Shared to Other Computers" under method, which seems useless.
Is there some easy way to make the router use the Internet connection used by the Ubuntu box for the LAN?