I have a Linksys wireless router and it worked fine with my Motorola modem and Comcast service until a few days ago. After many hours, I got it working again, but I couldn't get the Dynamic IP to work, so set the Static IP address. I understand that comcast swithes IP address every couple of days, which means I have to reset my IP address. Did Comcast change something so the dynamic address won't work? I couldn't get the Host Name and Domain names to work. What should they be: comcast.net or attbi.com? Any help would be appreciated.
You can't use a static IP address. If you get caught using a static ip that's assigned to someone else, you will get banned. And you're right it won't work after about 4 to 7 days (depending on how long a DHCP lease is in your area).
Comcast does not use and ignores domain name and host name, so forget about it, it's irrelevent.
The thing to do is set things back up the way it's supposed to be and power cycle everything starting with the cable modem, thent he router, then the PC. IF still having trouble, clone the MAC of the PC into the router. and then power cycle the cable modem then the router again.