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Motorola SBG6580 cable modem into Bridge mode on Bright House Networks

With a giant hat tip to Anthony Volodkin of The Hype Machine, I now give you detailed instructions on how NOT to use your Motorola SBG6580 cable modem as a router (aka putting it into Bridge mode). Of course, it is a very good cable modem but it is not, in my opinion, a very good router. These instructions are 100% accurate for the cable modems that Bright House Networks of Central Florida give to customers. Your ISP may have a slightly different version of the Motorola SBG6580.

Here are the step-by-step instructions:

1. Unplug the coaxial cable from your Motorola SBG6580 cable modem.

2. Hold down the reset button on the back panel with a pen for 30 seconds.  This resets all settings to factory defaults.  The modem will be auto-reconfigured once you plug in the coax cable.

3. When the Motorola SBG6580 modem is back on, plug an Ethernet cable into your computer and then plug the same Ethernet cable into the modem. The port you use is not that important, but to keep it simple, use Port #1.

4. Your computer should get a LAN IP address of, and you should be able to connect to and login with "admin" and your password that your cable company gives you. I was told explicitly by Bright House Networks that the old default password of "motorola" would not work, so I used the password they gave me. Of course, the login name is without the quote marks.

5. Now you will make some changes:

 * At the top of your cable modem configuration screen, click the Wireless link. Then click "Primary Network" on the left hand side. Then click Disabled where it says "Primary Network" (in the middle of the page). This will disable the wireless features of the modem. You will be using your wireless router for all wireless features.

 * Now click Basic at the top of your configuration screen. Click Setup on the left hand side. You will see "Primary Mode" with a link called "NAPT Mode" directly under it. Click "Disabled" for this. This is one of the settings that makes the router into a simple bridge, meaning that your cable modem will simply hand off all traffic to your router instead of attempting to be a router. The Motorola SBG6580 cable modem will restart itself now. When it is back online after several seconds, continue.

 * Now click Basic at the top of your configuration screen. Click DHCP on the left hand side. You will see a heading that says "DHCP". You will see a setting that says "DHCP Server". Click the radio button that says "No".

 * Click Advanced at the top of your configuration screen. Now click "Options" on the left hand side. Check the box that says"Rg Passthrough". Then click the "Apply" button.

 * Type the WAN MAC Address of your wireless router into the "PassThrough Mac Addresses" field, then click the "Add Mac Address" button. Be sure to put colons ( : ) between every two numbers or digits (example: 01:23:45:67:89:AB). You should be able to find your MAC address somewhere on your wireless router. If not, I am sure you can find it at the manufacturer support page. For example, the support page for Linksys is


6. Connect port 1 on the Motorola modem to the WAN port of your wireless router.  Plug the coaxial cable back into the modem and power cycle it (meaning, turn it off completely by unplugging it for 30 seconds and then plugging it back in). If you have to power cycle it more than once, don't worry.

7. Once the four lights on the modem are lit up, your wireless router should have requested and received a public (WAN) IP address from your ISP.  If this is not the case, click to "Renew Lease" in your wireless router interface. If you are still having problems, do this: 1- reboot the cable modem by using Status (at the top of the configuration screen) ---> Configuration (on the left hand side) ----> Reboot; 2- After the cable modem is totally rebooted, THEN reboot your wireless router; 3- After your wireless router has totally rebooted, THEN reboot your computer, which will reset your NIC card. 

8- Congratulations ! You are now using the cable modem ONLY as a cable modem and your wireless router is doing the duty as the router.

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