Ok, here is my problem. I just recently changed from a dsl connection to comcast cable internet. Previously I took the internet connection from the dsl modem to the router. Using DHCP on the internet side. Then I had static ip addresses assigned to all my computers on the lan side. After switching to comcast I can no longer get on the net. If i plug the cable modem into the computer I can get a connection, but when I plug into the router I get no connection. I am using a linksys router..BF blah blah model number. what do I need to change to get my router to work. I would like to keep the static ip addresses on the lan side. Does comcast have some DNS addresses that i can write down. I know i can do the ipconfig/all but those addresses don't seem to work. mabye I have not done something right.
There's nothing you need to do except connect the router, and select the proper connection type. Since you didn't see fit to give us the exact Linksys router model you're using, I can't give explicit instructions. Most Linksys routers have setup pages at http://192.168.1.1 and the Setup page itself is where the WAN or Internet conenction type is typically configured. My WRT54G words it as "Automatic Configuration - DHCP". After you select this, I suggest you shut everything down, make sure all the physical connections are correct, then power up the modem and wait for it to connect to Comcast. Make sure the cable modem was off for at least 30 seconds. After it's connected, power up the router let it initialize. Then boot your systems. And you're done.
If you still have problems, then you need to provide more specific information, exact router model and firmware version, how it's configured, what OS is running on each system, and the TCP/IP setup on each system. One thing you need to be careful of is if you have a static IP scheme behind your router (which is fine), you need to make sure the DNS settings are correct if you have the DNS servers hard coded. Most the currect firmware loads from Linksys allow the router to be used as a DNS proxy (ie. you get 192.168.1.1 as the DNS server), but if this doesn't work, then you need to hard code the DNS servers from the router's DHCP lease from Comcast (on the Status page) into each system's DNS setup.