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    PfSense not replying to UDP traceroute on WAN

    Scheduled Pinned Locked Moved General pfSense Questions
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    • H Offline
      Harvy66
      last edited by

      Probably the "destination set to WAN address" part. The destination is probably not your firewall but something behind it. You could set it to destination of your LAN network.

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      • T Offline
        travisbrackett
        last edited by

        In my traceroute, I'm using the WAN IP address, and the packet capture confirms that the destination IP is the same one assigned to my WAN interface.

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        • DerelictD Offline
          Derelict LAYER 8 Netgate
          last edited by

          Try rejecting, not passing. This works for me:

          ![Screen Shot 2018-03-02 at 4.20.26 PM.png](/public/imported_attachments/1/Screen Shot 2018-03-02 at 4.20.26 PM.png)
          ![Screen Shot 2018-03-02 at 4.20.26 PM.png_thumb](/public/imported_attachments/1/Screen Shot 2018-03-02 at 4.20.26 PM.png_thumb)

          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

            Yup same rule here..

            wantraceroute.png
            wantraceroute.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 24.11 | Lab VMs 2.8, 24.11

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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 24.11 | Lab VMs 2.8, 24.11

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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)

                      1 Reply Last reply Reply Quote 0
                      • 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)

                          1 Reply Last reply Reply Quote 0
                          • 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 24.11 | Lab VMs 2.8, 24.11

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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 24.11 | Lab VMs 2.8, 24.11

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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 24.11 | Lab VMs 2.8, 24.11

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