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    TCP/IP Printing mangled across subnets

    Scheduled Pinned Locked Moved Firewalling
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    • S
      shawniverson
      last edited by

      Then what is the point of this setting, and why does it not completely disable packet filtering for this interface and leave the packets unaltered that route via the same interface?

      Static Route Filtering
      Bypass firewall rules for traffic on the same interface
      This option only applies if one or more static routes have been defined. If it is enabled, traffic that enters and leaves through the same interface will not be checked by the firewall. This may be desirable in some situations where multiple subnets are connected to the same interface.

      I agree that a network shouldn't be asymmetric, but the presence of this setting and the unexpected behavior should be cause for some concern.

      johnpozJ 1 Reply Last reply Reply Quote 0
      • DerelictD
        Derelict LAYER 8 Netgate
        last edited by Derelict

        Your design is flawed so your network performance is sub-optimal.

        Different clients and network devices treat ICMP redirects differently. Your best bet is to design your network so such hackiness is unnecessary.

        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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        • S
          shawniverson
          last edited by

          Boy, you are dense and must not have read my earlier post or you would have realized that I have already redesigned my network.

          "Moving the downstream router to its own vlan to create symmetry resolves the issue."

          And you are dodging the issue. Static Route Filtering shouldn't be an option in pfSense if it is an unsupported configuration.

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          • DerelictD
            Derelict LAYER 8 Netgate
            last edited by Derelict

            It is not an unsupported configuration. It can "solve" (or paper over) a great many asymmetric routing cases.

            That it does not work for you in your specific case with your specific types of traffic does not mean the feature is broken.

            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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            • S
              shawniverson
              last edited by

              So it is supported. Well, then be advised that you cannot TCP/IP print across a Static Route Filtered interface, which results in packet level alterations that interfere with printing as long as the packet filter is enabled.

              You did not explain why that is happening or attempt to shed light on it, but with the push-back, I'll leave this here and rest my case.

              1 Reply Last reply Reply Quote 0
              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by Derelict

                @derelict said in TCP/IP Printing mangled across subnets:

                Different clients and network devices treat ICMP redirects differently.

                Actually, I did: "Different clients and network devices treat ICMP redirects differently."

                Packet capture analysis would be necessary to determine exactly what is breaking the flow.

                Good luck.

                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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                • johnpozJ
                  johnpoz LAYER 8 Global Moderator @shawniverson
                  last edited by

                  @shawniverson said in TCP/IP Printing mangled across subnets:

                  where multiple subnets are connected to the same interface.

                  That is just BORKED design out of the gate as well.. There is one valid reason when you would be running multiple layer 3 on the same layer 2... That is during the migration from 1 address scheme to another address scheme..

                  Something like running some link-local address space on that layer 3, at the same time as a global address.. But I wouldn't really count this as running 2 L3 on the same wire, since 1 of the address scheme's is only designed to be used on the same layer 2, etc.

                  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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                  • johnpozJ
                    johnpoz LAYER 8 Global Moderator @shawniverson
                    last edited by

                    @shawniverson said in TCP/IP Printing mangled across subnets:

                    avoid asymmetric configurations....

                    Told you that 2 months ago.. ;)

                    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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                    • S
                      shawniverson
                      last edited by

                      A packet capture and deep analysis revealed that ICMP redirects were the root cause of the failed print jobs. The printer appeared to not understand these packets. Lesson learned. Hopefully this will serve as a reminder to others to avoid asymmetric configurations....

                      DerelictD johnpozJ 2 Replies Last reply Reply Quote 1
                      • DerelictD
                        Derelict LAYER 8 Netgate @shawniverson
                        last edited by Derelict

                        @shawniverson said in TCP/IP Printing mangled across subnets:

                        The printer appeared to not understand these packets.

                        As soon as you stray
                        from the tried and true
                        You never know
                        what's going to screw you
                        burma shave

                        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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