Why cant i connect laptop to cable internet - works fine with dsl

[danntor]

Hello,
i have a laptop that I can connect to internet using ethernet LAN through an ATT router. However when I am away from home and no wireless available, I can't connect through a cable modem. I have been told that there is a setting change - however no one is able to say exactly which settings -- Any ideas???

 

[Guest]

Are you power cycling the cable modem before connecting it to your laptop?