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    Default deny rule IPv4

    Scheduled Pinned Locked Moved General pfSense Questions
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    • T
      tomli
      last edited by

      Hi All,

      Can I disable the Default deny rule IPv4? It block my Lan1 to Lan2 asymmetric route traffic.
      @9(1000106643) block drop in log inet all label "Default deny rule IPv4"
      [ Evaluations: 1283 Packets: 76 Bytes: 4080 States: 0 ]

      If I use the command "pfctl -d" to disable the filter function, Server A to Server B is working properly.

      Thanks,
      Tom

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

        @tomli

        Just place a rule that passes all ahead of it. Rules are done in order, with first match.

        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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        • johnpozJ
          johnpoz LAYER 8 Global Moderator
          last edited by johnpoz

          @tomli said in Default deny rule IPv4:

          Lan1 to Lan2 asymmetric route traffic.

          Why and the F would your traffic between lans be asymmetrical - if it is, that is what you should be fixing.

          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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          • T
            tomli
            last edited by

            Hi all,

            Just place a rule that passes all ahead of it. Rules are done in order, with first match.

            How can i set the user rule has the high priority then the default deny rule ipv4 rule set?

            Thanks,
            Tom

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

              Your not going to pass asymmetrical traffic.. Pfsense needs to see the syn to create the state..

              What the user needs to do is draw up their network, post it here - why would anyone on purpose want their network to be asymmetrical, and then do some hack on their firewall to pass said traffic.

              So we can discuss how to correctly set it up so its NOT asymmetrical

              2 possible work a rounds is source natting or host routing.. But the best solution is just to not do it in the first place.

              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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              • JKnottJ
                JKnott @tomli
                last edited by

                @tomli said in Default deny rule IPv4:

                How can i set the user rule has the high priority then the default deny rule ipv4 rule set?

                As I mentioned, those rules are processed in order and stop at the first match. Putting it anywhere in the list will put it ahead of the default deny will put it first. Firewalls normally start with just a deny all rule and you enable what you want by creating rules to allow it. If you really want allow all, just put it where you want it in the list.

                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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                • DerelictD
                  Derelict LAYER 8 Netgate
                  last edited by

                  That will only work if the blocked traffic is a SYN. That is pretty much never the case where asymmetry is involved.

                  I'm with @johnpoz . Fix the asymmetry.

                  If you really don't want to for some inexplicable reason, your best bet is checking the static route filtering box in System > Advanced, Firewall & NAT.

                  Chattanooga, Tennessee, USA
                  A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                  DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                  Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                  • stephenw10S
                    stephenw10 Netgate Administrator
                    last edited by

                    Yeah, the real solution here is to remove the asymmetric route.

                    However you can pass asymmetric traffic it just requires firewall rules with additional options:
                    https://docs.netgate.com/pfsense/en/latest/firewall/troubleshooting-blocked-log-entries-due-to-asymmetric-routing.html#manual-fix

                    Steve

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                    • johnpozJ
                      johnpoz LAYER 8 Global Moderator
                      last edited by

                      Bad idea to show users work a rounds that might be ok in a tech pinch where production needs to be up NOW, and you will actually fix it asap.. But give a user a button to press that allows what they are doing to function.. Be it a mess or not - and it will most likely stay that way.

                      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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                      • stephenw10S
                        stephenw10 Netgate Administrator
                        last edited by

                        Yeah, I hear you.

                        To be clear, if I wasn't, removing asymmetry should be the first option here. Sloppy state work-arounds are for when you have no other option.

                        Steve

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                        • DerelictD
                          Derelict LAYER 8 Netgate
                          last edited by

                          There is always another option. :)

                          Chattanooga, Tennessee, USA
                          A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                          DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                          Do Not Chat For Help! NO_WAN_EGRESS(TM)

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