Foo - Why won't my internet work?

I have Comcast and I can't get my Buffalo wireless router to work. It worked fine in my apartment. I just moved into a new house and Comcast gave me a new Motorola modem when they came to hook up the cable. I've hooked it up with the cable going into the modem, then a line going to the router, then the computer like the Buffalo user guide says. Then I tried a line going from the modem to the computer and another line going from the modem to the router, like the Motorola Modem guide said. Basically I've tried every combination from both user guides and I keep getting "Page can not be displayed" when I try to connect to the Internet.
The only way it works is if I just have a line from the modem to the computer and nothing else hooked up.
WHY?????

Probably the router configuration is incompatible with the new modem. Verify your settings.

Do a hard reset of the Modem. I had a similar issue when I was trouble shooting a computer, because some routers will remeber the MAC address of the computer hooked to it (or something like that, don't remeber the exact reason any more) so when I tried to move it over from the computer to the router it wouldn't work because whatever it was checking didn't match up. After doing a hard reset on the Modem (pushing in the little button for 5 seconds) it synched up properly with the router and the interwebs was mine.

I have Comcast

Answered your own question. ;)

If it works directly to your PC and through the router, you may have to set up your router with the same MAC address as your PC's NIC.

The configuration should be Cable > Modem > Router > PCs Ensure the network cable from the Modem to the Router is connected to the router's WAN port and that you are not using a crossover cable.

I have Comcast and I can't get my Buffalo wireless router to work. It worked fine in my apartment. I just moved into a new house and Comcast gave me a new Motorola modem when they came to hook up the cable. I've hooked it up with the cable going into the modem, then a line going to the router, then the computer like the Buffalo user guide says. Then I tried a line going from the modem to the computer and another line going from the modem to the router, like the Motorola Modem guide said. Basically I've tried every combination from both user guides and I keep getting "Page can not be displayed" when I try to connect to the Internet.
The only way it works is if I just have a line from the modem to the computer and nothing else hooked up.
WHY?????
With it working in this setup: cable > modem > line > computer, do this:


Turn everything off.
Unplug the line from the modem to the computer.
Plug that line into the router.
connect the router to the computer
turn on the modem and wait until the lights indicate it is happy
turn on the router and wait one minute
boot the computer
see if you can get online


If that does not work, see if you can get to the config screen on the router from your browser. The address or url to do that should be in the router manual. If you can't, then turn everything off and repeat the above steps, except swap the modem->router line with the router->PC line. Can you get to the router config screen if you do that?

If you can get to the router config screen, look at the options for MAC address spoofing, like chipcom mentioned.

Both your devices are DCD. Your computer is a DTD device, that's why the computer works and the router doesn't. To get two like devices to talk you need a crossover cable. If you aren't using a crossover cable between the router and modem then it will never work.

If, when you plug the modem into the router, the WAN light doesn't come on, then it most likely is a cabling issue.

However, I don't think it is that, and IIRC, most newer routers have autosensing on the WAN port, because people will use the cable that came with the router, the cable that came with the modem, or just any old cable lying around.

Something needs to be cleared up. When you said:

"""Then I tried a line going from the modem to the computer and another line going from the modem to the router"""

At the same time??? How many places do you have in the back of the Motorola modem to plug things in? Does the Motorola modem have a switch/router built in? If so, then you don't need your router and that is your problem (you can't simply daisy chain routers together without changing settings that most people don't even know exist).

If your modem is JUST a modem, then you will only have places for the power cord, the cable, and the Ethernet cable going to the [computer, router]. (Sometimes there is a USB port, too.) If you have MORE ports than that (i.e. 4 places where your Ethernet cable will go), then you likely already have a built in router/switch. Most DSL isp's have an all-in-one like that, but generally not cable ips's. If you do have an all-in-one ("Gateway Modem") then just run the cable to the modem and the Ethernet cord to the computer.

Unless I missed something and am just comfused...

Actually, even in that case... the router's wireless, so if he wants to use a laptop... he still needs to use the wireless router.

I have done that before - put a wireless router behind a wired router - when the wireless router didn't support some features I needed, but was just for one computer, so I stuck that one computer in the DMZ, and went on with life.

Both your devices are DCD. Your computer is a DTD device, that's why the computer works and the router doesn't. To get two like devices to talk you need a crossover cable. If you aren't using a crossover cable between the router and modem then it will never work.If he plugs the modem into the WAN port of the router, a straight-through cable works just fine.

Try HelmetHead's method of plugging the modem directly into the computer to remove the router as a possible problem. If you can't get internet-access with computer hooked directly to modem, there's a configuration problem of some sort on the ISP's side. Or there's a cabling problem. The lights on the modem should tell you whether it's getting the correct signal.