How to configure for Comcast Internet

1. Shut down the Mac.
2. Unplug the power from Comcast modem.
3. Connect the ethernet cable between the Comcast modem and your Mac.
4. Power on the Comcast modem and wait for the cable light to come on solid and not flash.
5. Turn on the computer.
6. Apple menu -> System Preferences -> network -> Show connections
should show the ethernet with a green circle next to it. If it is yellow or read, try to configure your ethernet and check if PPPoE is enabled. If it is, disable it and restart your Mac. Start step 6 again, and tell us what your settings say on your screen in the Network preferences if the ethernet is still yellow or red.

There's nothing to configure. Just plug in the ethernet cord to the computer, you'll receive an IP address soon there after, and you're done.

The reason I mention the extra steps, is if the modem was hooked up to a different computer, sometimes it needs time to reset itself. This usually takes about 45 seconds.