I don't own an Asus (so I don't know which Linux distribution they run), but the principles involved are fairly simple. Here's a few issues that you might look into:
- Do you know how to set network connection properties on the ASUS? Is there a control panel icon for that? Or can you click on the 'red x' and change those settings? You may need to change some settings depending on your DSL setup.
- How did you set up DSL on your Windows/Mac machines? Did you just plug the computer in, and it figured everything out? Or did you have to input an ip address, subnet mask, etc.? The former is called DHCP addressing, and the latter is called static addressing. If you had to set up static addressing on your Windows/Mac machines, you'll have to do the same thing on your ASUS.
- Are you using the right kind of Ethernet cable? There are two kinds -- straight and crossover. Choosing the right one might depend on your DSL modem (and any other intermediate devices you use, like a network switch).
- Did you say the DSL connection is /not/ working on you other computers now? Or is it? Do you have all your computers connected to the DSL modem? Or is there other devices involved? If it doesn't work on any of your computers, you may need to configure the modem through the HTTP interface.
Wireless connections can be hard to set up on Linux, but Ethernet is never hard if you know what you are doing. (Or know someone who does.) If you can tell us everything you know about your setup, we should be able to help you work through this.
PerlCoder (http://indicium.us)