I just moved into my new home and bought CM100 cable modem and WRT54GL router. The Comcast guy set up the cable modem to connect right to the laptop and it works fine that way. However if i plug the router to the modem i'm unable to connect thru the laptop. I can get to the router's web interface and i try to make it Renew IP but it keeps returning 0.0.0.0. I have tried using ethernet and wifi but it doesn't make a difference. What am i missing?
Probably the internet connection is still locked to your laptop (i.e. the MAC address of the NIC inside the laptop). Your ISP only allows you to have a single internet connection active at a time. If you connect the laptop and then connect the router, the laptop will have internet but not the router.
Possible solutions for this:
1. Use the MAC Address Clone function in the router to clone the MAC address of the laptop.
2. Reset the modem and then start it up while it is connected to the router.
3. Keep the router connected through the night. Usually after a few hours of inactivity your ISP will clear the lock on your internet connection and will accept the different MAC address of your router.
When the Comcast guy was over he only grabbed the MAC (ethernet, not USB) from the cable modem, though. Is there a way to get into the modem, like a web interface, to see if there is a bridge setting or something that needs to be changed?
1. There is probably a web interface for the modem. Most devices nowadays have a web interface. You have to check the manual of your modem for that or ask Comcast.
2. But this has nothing to do with the problem. The MAC address of the modem has nothing to do that your internet connection will only work for a single device at a time. Use the MAC address clone, reset the modem (if it has a reset button, otherwise just unplug it from power and then back), or let it run through the night with the router connected. You don't need access to the modem for this nor do you have to change anything on the modem.