4 Replies Latest reply on Feb 7, 2011 3:31 PM by rcamm

    Changing Direct Connection to PPPoE

      It's possible that I'm going to change my internet connection from SDSL to ADSL2+, because that is much cheaper and gives me much more downstream bandwidth. They provide a modem and, for a fee, a router. I want to avoid the fee and put the Snapgear behind the modem. I don't know yet if they use PPPoE and if the modem is in bridged or routing mode, but I want to prepare in case I have to use PPPoE. I checked the user manual and also KB. It's not clear from these documents how I can change "Direct Connection" to "ADSL". How do I do that. I do not find any such option. The user manual mentions a "Change type" list on the connections page, but there isn't one.


      Also, I have a question about bridged vs. routed mode. The manual says that with routed mode I can continue using Direct Connection and the PPPoE is done by the modem. But lists as disadvantages that you have to make port-forwards etc. twice on both devices. Are you sure about that? As further background: I have a static public subnet. If I understand right, routed mode means that the modem gets "my" IP address. In this case it gets *one* IP address from my subnet and I should be able to assign the other IP addresses to the Snapgear behind it and the other machines in the LAN. So, just like I have it now. Currently there is an SDSL router in front of the Snapgear and it's got one of the IP addresses of my subnet and the Snapgear is in bridging mode for the public addresses and does NAT for private addresses. Shouldn't I be able to get just the same with the modem in routing mode? If this would be working with routing mode it looks like this is preferrable because I don't have to change the Direct Connection and don't have to setup the Snapgear for PPPoE.



        • 1. Re: Changing Direct Connection to PPPoE

          For clarification, with "bridged vs. routed mode" I mean that mode on the modem.

          • 2. Re: Changing Direct Connection to PPPoE

            sorry for the delayed response....the office floated down the Brisbane river, and then my internet connection at home got killed


            if you delete the connection you should get the ability to select ADSL. Take a backup first


            the manual is correct. 'routed mode' is not truely routed...it basically means that the modem will perform NAT. I doubt the modem could be configured to do true routing instead, but you should check the user guide.


            So you use routed mode on the modem, it will still NAT your public block  ;(


            The simple method is to test it out....I think you will find it easy to convert to ADSL, and if you have issues, restore the backup.


            You should ensure you are running the latest firmware in the generation of firmware you are using, ie if you are on version 3, ensure you are running the latest version 3 firmware. This will ensure that any ADSL bugs are not present that may be in earlier versions.

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            • 3. Re: Changing Direct Connection to PPPoE

              Hi Ross, I hope you and your family are still well, as I understand there's now a hurricane in that same area. I wasn't aware that you are located in AU, so you've maybe been there since the early Snapgear days?


              As it appears the modem will indeed be in bridging mode. I still have an older Snapgear around and will test the switch to ADSL on it. It's just a pity that all other connection-specific settings will probably be gone, too, when I delete the direct connection. I have both NAT and bridging mode set up and rearranging that needs some care.

              Oh, wait, I'm just reading up on bridging in the user manual. That says I can configure a bridge only on a direct connection. That sounds not promising. So, if I go to ADSL and a bridging modem I cannot transparently bridge my public subnet anymore. How do I make use of it then? Do I have to attach all IP addresses of the subnet to the Snapgear and then route these one-by-one to a private IP address?

              Not good :-( In that case I better stay with SDSL, although ADSL comes me 2/3 cheaper.

              • 4. Re: Changing Direct Connection to PPPoE

                Bridging is an ethernet technology.  PPP is not (even if it is PPPoE).

                You can't combine the two.


                You may be a able to disable NAT on the SG and use routing instead.

                There's two ways this might work, but I can't guarentee either.


                1. In theory, you should be able to have the same IP address assigned to both the PPPoE connection and the LAN interface on the SG.  But I wouldn't be surprised if we have assumptions in the code that the addresses will be different.


                2. If you have a spare public address, then assign that to the LAN interface.  We might still have some bad assumptions in te code, but this is more likely to work.


                Neither of these are for the faint hearted though.  If you get one mostly working, I'm happy to look at a TSR via support and suggest custom rules.


                Otherwise the only way is to give the addresses to the SG and use lots of NAT, like you say