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    Able to ping, nslookup and curl in pfSense box but curl failed in clients

    Scheduled Pinned Locked Moved General pfSense Questions
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    • M
      mltobing
      last edited by mltobing

      @stephenw10 The NIC assignment were correct. If I set them wrong, WAN interface didn't get any IP Address.
      Because this is initial setup I didn't change any hardware offloading setting.

      I tested again and this time I captured OpenWRT LAN interface. pfSense WAN directly connected to OpenWRT LAN.
      Traffics forwarded from my laptop don't have TS val, but from pfSense have.

      7166526b-cc8b-4a85-9df0-4eabf82c73c9-image.png

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      • stephenw10S
        stephenw10 Netgate Administrator
        last edited by stephenw10

        Ok so pfSense is sending that traffic as expected and OpenWRT sees it on the LAN but no replies.
        Are there any replies on the OpenWRT WAN?

        You're probably going to need to open that in Wireshark and look at it more closely.

        You might also connect the laptop to OpenWRT directly and pcap the same traffic there when it succeeds.

        https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_timestamps

        TCP timestamps are enabled by default In Linux kernel.,[27] and disabled by default in Windows Server 2008, 2012 and 2016.[28]

        Steve

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        • M
          mltobing
          last edited by mltobing

          @stephenw10 I am not familiar with packet inspection. Is there something I need to check ?

          This is the packets capture result on OpenWRT LAN interface

          Top = my laptop => pfSense => OpenWRT (unable to connect to internet, no reply from OpenWRT WAN)
          Bottom = my laptop => OpenWRT (able to connect to internet)

          370c29be-8274-41ec-b191-7f50559d965c-image.png

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          • stephenw10S
            stephenw10 Netgate Administrator
            last edited by

            OK, it looks like you may have some asymmetric routing somewhere.

            In the working pcap you can see there is traffic in that TCP session that did not pass the interface.

            By far the most likely is that the laptop you're testing from has some other connection. Like maybe it has wifi directly to the ISP "modem".

            pfSense will block out of state TCP traffic like that. Lesser firewalls may not. ๐Ÿ˜‰

            Do you see any blocked TCP traffic in the pfSense firewall log?

            It's still hard to see how that could happen though because each device is source NATing on the way out...

            But that fact the ping works also points to that.

            Steve

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            • M
              mltobing
              last edited by

              @stephenw10 I did so many tests but traffics filtered by destination only these

              84d600e1-2cf3-4753-b79c-84cb15aaa8cd-image.png

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              • stephenw10S
                stephenw10 Netgate Administrator
                last edited by

                Hmm 192.168.1.101 should not be blocked inbound on LAN like that. Assuming that's still the LAN subnet?

                But if it was that traffic would not appear on the pfSense WAN

                Are you able to upload those pcaps so I can review them?
                https://nc.netgate.com/nextcloud/s/9jFb69WaCHzfSRB

                Steve

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                • R
                  rcoleman-netgate Netgate @stephenw10
                  last edited by

                  @stephenw10 That is a SYN packet - it could be because of a closed state or a bad state reference (like you commented about asymmetry).

                  Ryan
                  Repeat, after me: MESH IS THE DEVIL! MESH IS THE DEVIL!
                  Requesting firmware for your Netgate device? https://go.netgate.com
                  Switching: Mikrotik, Netgear, Extreme
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                  • stephenw10S
                    stephenw10 Netgate Administrator
                    last edited by

                    SYN should be passed. Any other flag combo might be dropped. Hard to see where another route might exist though since the laptop is already connected via wifi.

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                    • M
                      mltobing
                      last edited by mltobing

                      Files uploaded. I thought I disabled the wifi during the test

                      bca43064-33cd-4252-b993-be2abfe4019c-image.png

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                      • M
                        mltobing
                        last edited by

                        @rcoleman-netgate @stephenw10 @viragomann and the others on this thread. Thank you very much for your help.
                        This issue resolved after I checked "Disable hardware checksum offload" on System / Advanced / Networking (default uncheck).
                        I can access pfsense.org and other websites now

                        33745fc1-dca8-4390-9351-6f1fafa22e1d-image.png

                        2021394c-f1a9-4827-aaa5-d42387a265f8-image.png

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                        • stephenw10S
                          stephenw10 Netgate Administrator
                          last edited by

                          Ah, that will do it. I should have pressed that question when I asked it earlier. Lesson for today.

                          Good result. ๐Ÿ‘

                          Steve

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