Sharing DSL internet connection with WRT54G

Question

I've recently changed from a cable to a DSL internet connection.
On cable I used a WRT54G router to share the connection to a laptop (via Wireless) and a desktop (via ethernet cable).
After instaling the DSL (modem and software) on the laptop, the conection doesn't work.
The set up for the linksys router was updated (changed to PPPoE, and informing the user id and password the provider gave me), via browser, and it is correct.
Now, I can only access the internet when the ethernet cable is connected straight from the DSL modem to the laptop.
If change the cable from the laptop to the linksys router and try accessing the router, it doesn't work, although the connection is indicated as active, and the laptop gets the ip I defined in the DHCP linksys router (192.168.1.100).
Under this scheme, it seems the laptop can't find, neither the linksys router, nor the DSL modem (modem model is Thomson Speed Touch 510 v6), and hence, the internet.
Due to that when I try accessing the Linksys configuration page (192.168.1.1) I receive a message that this page cannot be accessed offline and it's necessary to connect. I can't connect, cause the modem is not found in the net.
That should not happen, the page should be available offline, cause it's a connection that does not rely on an internet connection (the router is close to the laptop).
The same problem occurs with any web page I try to open/load: a message stated it can be accessed offline, and it's necessary to connect, but, again, I can't connect.
I tried using a cable between the laptop and the linksys router, but did not go any better.
Thx everyone

Answer 1

It is my understanding that the Thompson Speed Touch 510 V6 is an ADSL Gateway modem router.   As such, at a minumum, it is probably doing your PPPoE login for you.  If this is correct, then your Linksys should not be set to do a PPPoE login.  When you used software to install your modem, didn't you have to enter your user id and password and have it loaded into the Thompson?  If the Thompson has this info, the Linksys pobably does not need it.
You really need to talk to your DSL provider, or check their web site, to see what they suggest about setting up your system.  At a minumum, you will need to know exactly what the Thompson is doing:
Is it doing your PPPoE login?
Is is acting as a DHCP server?
In the mean time, you might just want to try the following:
Try setting the router to "Automatic Configuration - DHCP"
If you are having trouble getting to the router setup page, do the following:
1)  power down your modem, router, and computers, and unplug them from the wall.
2)  disconnect all wires from the router.
3)  connect one computer by wire to port 1 (not the internet port) on the router.
3)  power up the router and allow it to fully boot (1-2 minutes).
4)  power up the computer
5)  open your browser and point it to 192.168.1.1  This should open the router login window.  Enter your user name (if any) and password.  This should take you to your router's setup page.
If you get this far, set the router to "Automatic Configuration - DHCP", save the setting, then power down the router and your computer.  Then reconnect modem-router-computer and try your setup again.
If any step fails, note the exact error message and the status of the lights on the router.  Report back with your results.  Also, it might help if we knew your DSL service provider.
Hope this helps. 
Message Edited by toomanydonuts on 12-23-200602:29 AM
Message Edited by toomanydonuts on 12-23-200602:31 AM