So I have comcast with a cable modem. The cable comes into my house and I have a splitter in the basement. One cable run goes to the first floor and another goes to the second floor. The modem from comcast is on the first floor. I want wired ethernet access on the second floor. My idea is to just buy another cable modem (surfboard?) and hook it up on the second floor cable. Will this work? Or does comcast somehow know each and every cable modem in its network? I was poking around the interface of the comcast modem and there is a utilities tab. In this tab is a button that says 'ISP only' Clicking this button brings up a dialog with 'password of the day'. Are these the settings that the cable guy has to set so the modem works? Since I already pay comcast for one modem, shouldnt I be able to add as many modems as I like to the line? I actually want separate wired LANs.