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    Can't get an IP from ISP behind switch

    Scheduled Pinned Locked Moved DHCP and DNS
    20 Posts 3 Posters 872 Views
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    • johnpozJ
      johnpoz LAYER 8 Global Moderator @JKnott
      last edited by johnpoz

      @JKnott they give you an 8 port 10ge switch for "free" with the service - that is pretty freaking nice of them for sure.

      And they hand out multiple public public IPv4 - without added charges, if the rates are reasonable those seem like great bonus to go with them over some other isp that doesn't do that..

      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

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

        @johnpoz

        I believe it's $300 (Cdn) per month for 8 Gb. And no, there's no extra charge for the IPv4 addresses. Just plug in whatever you want and it works. I don't know if there's a maximum, for example if you had a 48 port switch. But I have had 2 IPv4 addresses for years.

        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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        • S
          sef1414 @johnpoz
          last edited by

          @johnpoz

          Hmm, yeah. Sorry. I missed that in your first post, thought you were just meaning 2nd pfsense should have the same settings. I did not try setting it to a static IP on secondary, I had it set as DHCP, as the IP is dynamic. I will try doing that though.

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          • S
            sef1414 @JKnott
            last edited by

            @JKnott

            I did try some packet captures, though I'm a bit inexperienced at that level of detail. All I could see was IP 0.0.0.0 sending requests to a subnet mask like 255.255.255.x and not getting any response. I will re-create and actually copy that info.

            JKnottJ 1 Reply Last reply Reply Quote 0
            • JKnottJ
              JKnott @sef1414
              last edited by

              @sef1414

              At the start of the DHCP sequence, before it has received any info, the client will broadcast the request and use 0.0.0.0 as the source address.

              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...

              S 1 Reply Last reply Reply Quote 0
              • S
                sef1414 @johnpoz
                last edited by

                @johnpoz

                Alright, I gave it a go. Changed secondary WAN config from DHCP --> Static, and input the IP fetched from DHCP on the primary box. No dice. Can't get any connectivity.

                It showed up on assignments page, but no connectivity and gateway status page showed 100% packet loss.

                e472724b-87c8-4ac1-b380-11f4fe24e39b-image.png

                I'm really stumped here, only way I can get an active connection is by removing the cloned MAC spoof, and then power cycling the modem.

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                • S
                  sef1414 @JKnott
                  last edited by

                  @JKnott Yep, this is all I saw on the packet capture

                  johnpozJ 1 Reply Last reply Reply Quote 0
                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator @sef1414
                    last edited by

                    @sef1414 so you sure your clone mac is the same? If you say it works when you use the native mac and just power cycle the modem it points to your clone mac not being correct..

                    In your packet capture - you see the correct "cloned" mac?

                    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

                    S 1 Reply Last reply Reply Quote 0
                    • S
                      sef1414 @johnpoz
                      last edited by

                      @johnpoz Pretty sure. It was copied from the MAC address field of the interfaces status page on the primary box. Just verified that it is correct. Perhaps I'm missing something.

                      Guess I will need to do a more verbose packet capture?

                      All I saw was these lines on repeat:

                      13:21:56.318459 IP 0.0.0.0.68 > 255.255.255.255.67: UDP, length 300

                      johnpozJ 1 Reply Last reply Reply Quote 0
                      • johnpozJ
                        johnpoz LAYER 8 Global Moderator @sef1414
                        last edited by

                        @sef1414 or just download it and look in say wireshark

                        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

                        S 1 Reply Last reply Reply Quote 0
                        • S
                          sef1414 @johnpoz
                          last edited by

                          @johnpoz

                          Alright so I was able to do some more testing, and it is pretty bizarre compared to what I believe should be expected behavior.

                          I've checked a countless times at this point to ensure the MAC from my primary box is set on the WAN interface of the secondary box. I would expect that my modem can not tell the difference between the two boxes, and both pfsense boxes should be able to grab the same IP from my modem if I disable the WAN interface on one of them, or even perhaps both simultaneously, though I would expect issues in that scenario.

                          Here are the steps I took with the results:

                          • On pfsense primary, put down WAN interface via ifconfig in SSH session
                          • Physically plug ethernet cable from pfsense secondary into trunk port 5 on switch
                          • Pfsense secondary shows WAN connection as up, but doesn't receive an IP address
                          • Unplug pfsense secondary from trunk port 5, and plug it into trunk port 1 (where pfsense primary was previously plugged in)
                          • Pfsense secondary obtains an IP quickly (without modem reboot) and has connectivity - With a different IP address!
                          • Unplug pfsense secondary from trunk port 1, replace pfsense primary into trunk port 1. - Pfsense primary grabs the previous IP.

                          I could see it possibly being a switch configuration issue, though I've been over that a dozen times as well. That would not explain pfsense secondary getting a different IP though. My best guess is MAC spoofing is not working somewhere between the interface and modem.

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