I recently got Covad ADSL to act as a backup internet connection. Comcast is fast, and cheap, but not always reliable, and I hate to have downtimes because of them. By default Covad gives you a Netopia-3000 which is a classic all-in-one piece of crap. It is a router, wireless access point and a DSL modem all rolled up into cheep bluish plastic case.
By default the device is set up like this:
- Enabled NAT with DHCP
- Enabled open Wifi
- Blocking all Inbound Traffic
This was exactly the opposite of what I needed. I simply need a DSL modem to sit outside my Sonicwall TZ170. All I really want is a piece of hardware that can translate the DSL moonspeak into proper Ethernet signals that the firewall will understand. I looked around but I couldn’t find good tutorials on how to accomplish this so I decided to make my own.
First you will need to configure the Netopia router. So connect it to any computer, and pull up the web interface at 192.168.1.1. By default both the username and password are admin. Don’t forget to change that!
First navigate to Advanced Configurations and choose Internet Security. We don’t want Netopia doing any kind of Firewall like stuff. This is what the Sonicwall is for and it does it much better. So check Allow Sever Hosting on this screen.
Next, got to NAT Applications, and choose OFF from the combo box. NAT is bad. We want the firewall to have direct access to the outside world – not sit on a NAT. You might be prompted to restart the router after you change this setting.. Once you log back in, this screen should look like this:
In LAN Setup un-check the DHCP option. This may or may not prompt you to restart the router again. You want your screen to look like this when you are done – just the Router IP and Subnet should be visible:
Finally, go to WAN Setup. Don’t touch the values of VPI and VCI. Make sure the Protocol is PPP over Ethernet LLC/SNAP. Set Bridging to Enabled.
This will definitely force you to reboot the router. After this you won’t have internet connectivity on that machine. That means it’s working. Your Netopia just became a DSL modem and you will need a PPPoE client to use it. Disconnect it from your machine, and plug it into the Sonicwall’s WAN port.
Get into your Sonicwall control panel, and open the Network section. There, choose NAT with PPPoE Client from the pull-down menu:
You should see an automatic popup window. If you are with Covad like me, you can safely ignore the General tab. It will be overwritten anyway. Switch to the PPPoE tab and enter your username and password.
You obtain them from your ISP – and no, they are not the same as the credentials you use to sign into covad.net. Both username and password fpr PPPoE are just random character strings composed of letters and numbers and some non-alphanumerics like @. Covad actually puts them on the packing slip that comes in the box with the router.
Be sure that you typed in your credentials correctly. As far as I could see there was no meaningful error messages if you get them wrong. You still get an IP, but there is no internet connectivity.
Once you get it set up, go get a cup of coffee. Sometimes it will take 2-3 minutes before the two devices figure out how to talk to each other. No clue why, but I was fighting with it for around 10 minutes, then got interrupted, went to do something else, and all of a sudden the internet “fixed itself” as I was told by a coworker. :P
So there it is. I hope it helps you, and spares you some unnecessary frustration.
[tags]covad, netopia, netopia 3000, sonicwall, sonicwall tz170, dsl, adsl, modem, router, firewall[/tags]