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    Trying to access my Comcast modem via the LAN

    Scheduled Pinned Locked Moved General pfSense Questions
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    • JKnottJ
      JKnott @JKnott
      last edited by

      @JKnott said in Trying to access my Comcast modem via the LAN:

      Can you or Comcast put that modem in bridge mode?

      After a couple of seconds of hard Googling, I found this. This is the sort of thing I did with my modem. I put it in bridge mode and let pfSense handle everything else.

      PfSense running on Qotom mini PC
      i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
      UniFi AC-Lite access point

      I haven't lost my mind. It's around here...somewhere...

      chpalmerC 1 Reply Last reply Reply Quote 0
      • chpalmerC
        chpalmer @JKnott
        last edited by

        @JKnott said in Trying to access my Comcast modem via the LAN:

        After a couple of seconds of hard Googling, I found this.

        From that page-

        "Cannot have a fixed Static IP assignment"

        Triggering snowflakes one by one..
        Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

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        • JKnottJ
          JKnott @chpalmer
          last edited by

          @chpalmer said in Trying to access my Comcast modem via the LAN:

          Comcast will not put the modem in bridgemode if you have static IP addresses.

          Does the line "Cannot have a fixed Static IP assignment" in the docs refer to the modem or your LAN? With my modem, there is no address I can reach from outside my network, but I can access it on the LAN side with an address in the 192.168 range. If you have a block of addresses, they should be able to route to use regardless of whether they use NAT or bridge mode.

          PfSense running on Qotom mini PC
          i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
          UniFi AC-Lite access point

          I haven't lost my mind. It's around here...somewhere...

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          • chpalmerC
            chpalmer
            last edited by

            The modem doubles as the local router for Comcast's purposes. With the static addresses I use with Wave Broadband the statics are forwarded to you. I have my pure bridge Motorola MB8600 in place before my repurposed XTM5 box here with a VIP for my statics. This is how I prefer it to be.

            Comcast uses their modem as a router on site. The IP's are routed to you via this method.

            So on the same interface you get NAT'd traffic and the routed IP traffic.

            Triggering snowflakes one by one..
            Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

            JKnottJ 1 Reply Last reply Reply Quote 0
            • JKnottJ
              JKnott @chpalmer
              last edited by

              @chpalmer said in Trying to access my Comcast modem via the LAN:

              The modem doubles as the local router for Comcast's purposes.

              Other companies do similar, but have addresses entirely separate from the customer's internet access. In those, putting the modem in bridge mode affects only the internet connection. by "Comcast's purposes", do you mean public "Xfinity" WiFi? If so, that's definitely a different address and has nothing to do with the modem mode. You'd be putting only your Internet access portion of the router into bridge mode, not the entire box. Think of if as 2 services sharing the same box.

              PfSense running on Qotom mini PC
              i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
              UniFi AC-Lite access point

              I haven't lost my mind. It's around here...somewhere...

              chpalmerC 1 Reply Last reply Reply Quote 0
              • A
                alpineaudio
                last edited by alpineaudio

                Is there a reason you want to stick with Comcast's modem router combo? Why not just get a Docsis 3.1 modem (https://www.arris.com/surfboard/products/cable-modems/sb8200/ gig ready). That's what I did and then went with my own router, that way I eliminated all their crap or issues.

                chpalmerC 1 Reply Last reply Reply Quote 0
                • chpalmerC
                  chpalmer @alpineaudio
                  last edited by

                  @alpineaudio said in Trying to access my Comcast modem via the LAN:

                  Is there a reason you want to stick with Comcast's modem router combo?

                  Yep he does. You need to read the entire thread to find it but he is using static addresses and Comcast requires the use of their equipment.

                  I'm really surprised there are not more Comcast savoy people reading this and chiming in. Its pretty well known information.

                  Triggering snowflakes one by one..
                  Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

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                  • chpalmerC
                    chpalmer @JKnott
                    last edited by

                    @JKnott said in Trying to access my Comcast modem via the LAN:

                    @chpalmer said in Trying to access my Comcast modem via the LAN:

                    The modem doubles as the local router for Comcast's purposes.

                    Other companies do similar, by "Comcast's purposes", do you mean public "Xfinity" WiFi?

                    No not the public WIFI crap. Speaking of crap we usually call them Comcrap due to "crap" like this.

                    By their purposes I mean in order to provide the static IP's they use a local router. (probably not the best use of "their purposes" but I digress.. The Modem/Router combination truly does the routing on site. If the OP was to show his "quality" logs you would see the ping is very small to the gateway router because that is indeed in the modem in this situation.

                    Triggering snowflakes one by one..
                    Intel(R) Core(TM) i5-4590T CPU @ 2.00GHz on an M400 WG box.

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                    • johnpozJ
                      johnpoz LAYER 8 Global Moderator
                      last edited by

                      Back on subject just create a vip

                      On your wan create a vip, lets call it 10.1.10.2, then create an outbound nat to that vip... There you go access.

                      An intelligent man is sometimes forced to be drunk to spend time with his fools
                      If you get confused: Listen to the Music Play
                      Please don't Chat/PM me for help, unless mod related
                      SG-4860 24.11 | Lab VMs 2.8, 24.11

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                      • B
                        bazzacad
                        last edited by

                        Thanks for all the help everyone. Sorry this became a longer topic then I expected. I'll try the VIP option this evening...

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                        • B
                          bazzacad
                          last edited by

                          So I want the VIP to be the destination for the outbound NAT?

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                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator
                            last edited by johnpoz

                            No the vip would be the interface for the nat, dest would be the IP your trying to get to or just the network.. One sec show you a pic.. I don't need it to access my modem.. But I can set one up real quick to show you. My modem which is bridged can still be access via is 192.168.100.1 address..

                            So create vip on wan say 192.168.100.2 - one sec brb.

                            here you go. Notice how I selected the vip as the translation in the outbound. You only need to use hybrid not manual.. So now anything coming from 192.168.9.0/24 network going to a 192.168.100.0/24 network will go out the wan using that IP..

                            vip.png

                            And there you go access
                            modemaccess.png

                            An intelligent man is sometimes forced to be drunk to spend time with his fools
                            If you get confused: Listen to the Music Play
                            Please don't Chat/PM me for help, unless mod related
                            SG-4860 24.11 | Lab VMs 2.8, 24.11

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                            • B
                              bazzacad
                              last edited by

                              Thanks for the screen shots. They're very helpful.
                              So I'm thinking this is what I'll try. Does it look correct...?
                              Also, my NAT mode is already set to Manual. Needed it for some PBX rules.

                              3e04464b-cf59-4cb5-85c4-e247f7469db2-image.png

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                              • johnpozJ
                                johnpoz LAYER 8 Global Moderator
                                last edited by

                                Yeah that looks right.

                                An intelligent man is sometimes forced to be drunk to spend time with his fools
                                If you get confused: Listen to the Music Play
                                Please don't Chat/PM me for help, unless mod related
                                SG-4860 24.11 | Lab VMs 2.8, 24.11

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                                • B
                                  bazzacad
                                  last edited by

                                  I added the VIP & NAP, but no luck. :-(
                                  I can ping the VIP & modem from the LAN.
                                  0d11ce55-5e3a-4d78-b016-1ff697db5809-image.png
                                  2885c82c-575c-42a7-aefa-ca1029f78803-image.png
                                  279cd2a6-a488-4324-baa8-f9f61b041492-image.png

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                                  • johnpozJ
                                    johnpoz LAYER 8 Global Moderator
                                    last edited by johnpoz

                                    Well you got something back.. Or you wouldn't have gotten that page.. So you got a syn,ack I would assume.. So your vip is working.

                                    Sniff on the wan when you try and open the page.. do you see the syn,ack come back from your syn.. If so pfsense is doing what you told it to do.

                                    Why did you do a /32? Set that to /24

                                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                                    If you get confused: Listen to the Music Play
                                    Please don't Chat/PM me for help, unless mod related
                                    SG-4860 24.11 | Lab VMs 2.8, 24.11

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                                    • B
                                      bazzacad
                                      last edited by

                                      OK I fixed the /32 thx.
                                      By Sniff do you mean WireShark?
                                      Or can I do it in pfSense?

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                                      • stephenw10S
                                        stephenw10 Netgate Administrator
                                        last edited by

                                        You can do it within pfSense:
                                        https://docs.netgate.com/pfsense/en/latest/monitoring/performing-a-packet-capture.html

                                        Steve

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