Internet Not Available with Comcast

[MinZhou]

I use SB6121 cable modem for Comcast. The router appears to be boot up but is not connecting to the internet. The link light on the cable modem flashes amber instead of blue, as with my old router.

[support]

@MinZhou By link light do you mean the ONLINE light (i.e., the globe)?

You might want to try copying the MAC address of your old router to the pcWRT router. Once you have the MAC address of your old router, go to the Internet Settings page of pcWRT. Paste the MAC address into the Override MAC address field, then click Save.

Let us know if you need help on how to find the MAC address of your old router. The process depends on the router model.

[MinZhou]

I found the MAC ID on the old router and put it in the Override MAC address field. It still does not work. The link light is the wave-like icon under the globe. when I plug in my old router, it immediately starts to flash in blue. I plug in the pcwrt router, it flashes amber. And the internet status in pcwrt control is always Down.

[support]

@MinZhou Thanks for the update! We should be able to work this out.

First of all, let’s make sure that the pcWRT router is functioning properly. Please do this test:
1. Remove the MAC address override in the pcWRT router and save.
2. Connect your old router to the cable modem.
3. Connect the pcWRT router WAN port to a LAN port on your old router.
4. Log in the pcWRT router console and check the Status page. Is Internet on?

We’ll decide what to do next depending on the outcome of this test.

[MinZhou]

I reset the router to its factory default (because it was set to the same SSID as my old router), then connected it to the old router. Now I cannot even connect to the control console via 192.168.10.1.

[support]

@MinZhou Because we are testing Internet connectivity, you don’t have to reset the router. Simply change the SSID, or turn off WiFi should work.

But since you’ve reset the router already, you’ll need to go back to the initial setup. You should be able to load the router console with 192.168.10.1.

To keep things simple, disconnect all wires from the pcWRT router. Then connect the power cable only, wait till it’s fully powered up. The SYS and WLAN LEDs should be solid on. Then connect your PC by Ethernet wire to a LAN port on the pcWRT. Load 192.168.10.1 to perform initial setup.

If the above step is successful, connect the pcWRT WAN port to a LAN port on your old router. Again, connect your PC to a LAN port on the pcWRT. Load 192.168.10.1 and look at the Status page. Is Internet up or down?

[MinZhou]

I created a different SSID as you suggested. I hooked the router to the old router. Now the internet works. But I don’t want to hook onto the old router. How can I hook it on to the cable modem?

[support]

@MinZhou So the pcWRT router is working as expected. The problem lies in the Internet connection. Do you know what type of Internet connection Comcast provides? Is it DHCP or PPPoE? If it’s the latter, Comcast should have provided you a user name and password to log on. You can get the connection properties from the management console for your old router.

My past experience has been that the connection is DHCP. However, Comcast checks the MAC address on their end. So when you change router, you won’t be able to connect. And that’s why I suggested that you try cloning the MAC address before. I don’t know how you retrieved the MAC address for your old router. You might want to check your old router’s management console. The MAC address might have been cloned there so it doesn’t match what’s on the box.

You may also contact Comcast tech support and ask them for help.

[Author]

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