Faux bridge mode with Sympatico and a locked 2wire modem
written by Ian McCracken
at Monday, June 30, 2008
Bell Canada locks their DSL modems, making it impossible to put them in bridge mode. Also, their port forwarding stuff (or "Application Support") doesn't really work. At least, I couldn't get it to work. All I wanted was to be able to get into my private Subversion repository from the outside, but try as I might, forwarding the appropriate ports to my server had no effect.
I went to Future World in hopes of purchasing a third-party DSL modem, but was informed by an employee that DSL modems were always ISP-specific and completely unavailable from other sources. Despite my certainty that this claim was utterly without merit, all the other stores were closed, so I didn't have much choice other than to mess with the modem I already had.
Eventually I hit upon a solution that worked for reasons I don't fully understand: separate subnets. I set the modem to be 10.42.0.1 and limited its DHCP range to a single address, so that the router would be the only thing getting its IP from the modem (the modem's "DMZPlus" feature requires that its target receive an IP via DHCP). I then set my Linksys router to get its Internet connection via "Automatic Configuration - DHCP", then set its IP to be 10.42.1.1 (note the different subnet). Finally, I reconfigured the DSL modem, putting the Linksys router in the DMZ. The Linksys pulled an IP from the ISP, all my local boxes were in the 10.42.1.0 network, the Linksys did all the proper port forwarding, and everything worked swimmingly, though I really don't understand how.
Unfortunately, Bell Canada kind of sucks. Turns out they're too expensive and they throttle torrents. I may switch to Teksavvy in the near future, which, since you buy your own modem, will make this solution irrelevant. But I half-learned something new about networking, so it isn't a total loss.
I went to Future World in hopes of purchasing a third-party DSL modem, but was informed by an employee that DSL modems were always ISP-specific and completely unavailable from other sources. Despite my certainty that this claim was utterly without merit, all the other stores were closed, so I didn't have much choice other than to mess with the modem I already had.
Eventually I hit upon a solution that worked for reasons I don't fully understand: separate subnets. I set the modem to be 10.42.0.1 and limited its DHCP range to a single address, so that the router would be the only thing getting its IP from the modem (the modem's "DMZPlus" feature requires that its target receive an IP via DHCP). I then set my Linksys router to get its Internet connection via "Automatic Configuration - DHCP", then set its IP to be 10.42.1.1 (note the different subnet). Finally, I reconfigured the DSL modem, putting the Linksys router in the DMZ. The Linksys pulled an IP from the ISP, all my local boxes were in the 10.42.1.0 network, the Linksys did all the proper port forwarding, and everything worked swimmingly, though I really don't understand how.
Unfortunately, Bell Canada kind of sucks. Turns out they're too expensive and they throttle torrents. I may switch to Teksavvy in the near future, which, since you buy your own modem, will make this solution irrelevant. But I half-learned something new about networking, so it isn't a total loss.
September 2, 2008 at 11:14 AM
Thanks for your post! Works perfectly!
I was getting very frustrated trying to get my new Linksys WRT610N to work with the Sympatico 2Wire modem/Router.
I'm even getting better speed results also.
July 4, 2009 at 5:14 PM
I found another way to automatically but the 2WIRE 2701HG-G (Bell Sympatico) into bridge mode. I reset the 2WIRE back to all defaults then connected my router and configured my router for PPPoE with my B1 ID and password. The WRT610N connected and obtained an IP, Gateways and DNSes directly from Sympatico. Note: you will no longer have access the 2WIRE web configuration.
August 25, 2011 at 7:55 PM
I have found an interesting way to get pppoe support behind the 2wire 2701 modem from bell canada.
I am using the stock firmware for the 2wire modem, wireless is disabled since I want to have full control over the wireless and use my linksys router for VPN terminiation.
The 2wire modem(router) is configured for pppoe with my b1 user id and password. I noticed that if I had my pc or any other deivce was connected to the 2wire modem, my linksys router (also conneced to the 2wire modem configured for PPPOE) was able to connect in bridge mode to establish it's own pppoe connection to bell.
If there was nothing (other than my linksys router)connected to the 2wire modem, the linksys could establish the PPPOE link. It looks like the 2wire blocks the pppoe packets until it has to open its connection. Once it starts it's own connection the 2wire modem will brige the PPPOE packets from my linksys router allowing it it start a PPPOE connection (with the same b1 userid and password).
All I needed was something to connect directly to the 2wire to open the first (always on) connection through the 2wire modem. In my case, I have a VoIP adapter that made a perfect always on device that I connected to the 2wire modem just so somehting was there to bring up the link. It would seem that any device that opens a connection to the internet directly attached to the 2wire modem would work.
My linksys router is the other device connected to the 2wire modem and it has been working perfectly establishing its own PPPOE connection just as it did with my old briging modem (SpeedStream 4200). This configuration has resulted in two conurrent PPPOE connections, each with its own IP@ (one from the 2wire, one from my linksys).
August 25, 2011 at 8:01 PM
Corrected statement:
... If there was nothing (other than my linksys router)connected to the 2wire modem, the linksys could not establish the PPPOE link.
September 13, 2011 at 3:34 PM
If your 2Wire is not listing a computer with a static IP address, or you would like the 2Wire to act as a bridged router, the 2Wire offer the technicians pages to change advanced settings:
h t t p://{router ip}//tech/configuration.html
This will bring you into the advanced configuration for the 2Wire. If you have a server with a static IP, and the 2Wire does not have it listed, it will not forward network/internet traffic to that computer. You can reset your local area network’s computer list. This will force the 2Wire to start rebuilding the list again and re-detect your server.
This this problem become common, consider placing the 2Wire into bridge mode and using your own router. This will require a static IP.
Shawn Zernik
http://www.internetworkconsulting.net