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    PfSense not replying to UDP traceroute on WAN

    Scheduled Pinned Locked Moved General pfSense Questions
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    • DerelictD Offline
      Derelict LAYER 8 Netgate
      last edited by

      that's a lot of NTP traffic…. :)

      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 Offline
        johnpoz LAYER 8 Global Moderator
        last edited by

        Yeah have a stratum 1 in the pool..

        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 25.07.1 | Lab VMs 2.8, 25.07.1

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        • T Offline
          travisbrackett
          last edited by

          That did the trick! Thanks!

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          • T Offline
            travisbrackett
            last edited by

            One weird thing I'm seeing is with Windows tracert which uses ICMP, pfSense sends a TTL expired reply when the request TTL is < 6, so I get a weird result where my pfSense firewall shows up 5 times. I don't want to reject ICMP packets, and I don't see a way to configure the TTL threshold. Anyone know of a remedy?

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            • DerelictD Offline
              Derelict LAYER 8 Netgate
              last edited by

              I would need to see a packet capture of that.

              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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              • T Offline
                travisbrackett
                last edited by

                Here you go. I've anonymized the pcap so 1.1.1.1 is the host running the traceroute, and 2.2.2.2 is my pfSense firewall. Looks like I was wrong and it stops sending a TTL expired, and starts replying, when the TTL is greater than 4.

                Edit: Oops, there's a 1:1 NAT and the replies are probably the routers in between and the host the packets are being NATted to.

                Edit: Packet capture on the LAN interface confirms this theory.

                icmptraceroute_anonymized.pcap

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                • DerelictD Offline
                  Derelict LAYER 8 Netgate
                  last edited by

                  OK you're kind of all over the place. You state that pfSense responds in the negative with a TTL > 4. What, exactly am I looking for?

                  What interface was that pcap taken on?

                  Anonymizing MAC addresses? Really? I can't help you.

                  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 Offline
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    "One weird thing I'm seeing is with Windows tracert which uses ICMP, pfSense sends a TTL expired reply when the request TTL is < 6"

                    From where to where?

                    I trace through pfsense to internet all the time, never seen such a thing..

                    singlepfsenseintrace.png
                    singlepfsenseintrace.png_thumb

                    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 25.07.1 | Lab VMs 2.8, 25.07.1

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                    • A Offline
                      axsense2
                      last edited by

                      What was the resolution? I am having the same problem as in topic. Tracing PFSense from outside PFSense seems that it is not recognizing traces at all. Ping works fine. It can't be true that PFSense does not work with Traceroute in UDP mode... can it?

                      Ax.

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                      • johnpozJ Offline
                        johnpoz LAYER 8 Global Moderator
                        last edited by

                        Ah screenshot is missing - prob got lost when they updated the forum... You juts need to set a reject rule on your wan for the udp ports. When get back from lunch can post up a screenshot.

                        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 25.07.1 | Lab VMs 2.8, 25.07.1

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                        • A Offline
                          axsense2
                          last edited by

                          Got it... I think. I created Rejected rule for UDP between ports 33434 and 33634. It actually resolves the issue.

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                          • johnpozJ Offline
                            johnpoz LAYER 8 Global Moderator
                            last edited by johnpoz

                            yup... that is all you need to do.

                            edit: for the next guy that finds this thread... I will post up screenshot of the rule
                            tracerouterule.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 25.07.1 | Lab VMs 2.8, 25.07.1

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