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    IPv6 traceroute not showing first hop (pfSense)

    Scheduled Pinned Locked Moved General pfSense Questions
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    • JKnottJ
      JKnott @johnpoz
      last edited by

      @johnpoz said in IPv6 traceroute not showing first hop (pfSense):

      So pfsense is actually seeing this traffic? Sniff on pfsense.. Setup packet capture on pfsense, then run your trace on your client... Pfsense actually sees the trace?

      Given that I can see the outgoing UDP between pfSense and modem, it has to pass through pfSense. As mentioned earlier, the problem is not pfSense passing the traceroute. The problem is that it doesn't respond to packets that die with hop limit of 1. I've attached the Packet Capture on pfSense of the outgoing UDP. Packet Capture, filtering on ICMP6, does not show any TTL exceeded messages.

      0_1548098773747_packetcapture.pcap

      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

        Where are you sniffing at? And 00:16:17:a7:f2:d3 is PFSENSE mac address?

        "Given that I can see the outgoing UDP between pfSense and modem,"

        And how exactly are you seeing that?

        If pfsense is not a HOP on your way to get where your going, then it will not respond if your "bridging" at pfsense..

        Are you doing any policy routing or multi wan setup for IPv6?
        https://www.netgate.com/docs/pfsense/routing/troubleshooting-traceroute-output.html

        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

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

          @johnpoz said in IPv6 traceroute not showing first hop (pfSense):

          Where are you sniffing at? And 00:16:17:a7:f2:d3 is PFSENSE mac address?

          "Given that I can see the outgoing UDP between pfSense and modem,"

          And how exactly are you seeing that?

          If pfsense is not a HOP on your way to get where your going, then it will not respond if your "bridging" at pfsense..

          Are you doing any policy routing or multi wan setup for IPv6?
          https://www.netgate.com/docs/pfsense/routing/troubleshooting-traceroute-output.html

          That was done with the pfSense Packet Capture, to show you that the UDP packets are heading out through pfSense. That MAC is for my desktop computer. I do not have any policy routing or multiwan setup. As I mentioned a few times, when I run Wireshark between pfSense and modem, I can see the outgoing UDP packets, but not seeing any returned ICMP6 TTL exceeded messages. This indicates that traceroute is leaving the desktop computer, passing through pfSense and out to the Internet. I don't understand why you're asking about things like policies, when it's obvious pfSense passing those packets out to the Internet. I mentioned that 4 days ago when I said: "They are also leaving pfSense and out to the Internet, as shown with Wireshark, between pfSense computer and modem. I'm just not getting any response from pfSense". At the moment, I'm not worried about ICMP6 TTL exceeded messages from any point beyond pfSense, as I have that ISP problem I mentioned earlier. That file I uploaded earlier, with the "CASA" MAC, shows the UDP packets leaving pfSense.

          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

            @jknott said in IPv6 traceroute not showing first hop (pfSense):

            That MAC is for my desktop computer.

            And how is that???

            0_1548100863064_tracertoute.png

            Where is pfsense mac in this trace... If pfsense is not a HOP, and doesn't lower the TTL then no it wouldn't respond with icmp..

            You see from my above sniff... That mac is pfsense interface.. and my raspberry pi sending the trace.. How is the dest mac in your sniff your PC? When it should be the mac address of your pfsense interface that is the gateway for your client doing the trace.

            I ask about policy routing because if you read that link, when doing that pfsense is not a hop in the path, and therefor will not send back icmp on your 0 TTL hop..

            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

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

              @johnpoz said in IPv6 traceroute not showing first hop (pfSense):

              @jknott said in IPv6 traceroute not showing first hop (pfSense):

              That MAC is for my desktop computer.

              And how is that???

              Where is pfsense mac in this trace... If pfsense is not a HOP, and doesn't lower the TTL then no it wouldn't respond with icmp..

              You see from my above sniff... That mac is pfsense interface.. and my raspberry pi sending the trace.. How is the dest mac in your sniff your PC? When it should be the mac address of your pfsense interface that is the gateway for your client doing the trace.

              On the desktop computer:

              2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
              link/ether 74:d4:35:5b:f5:fa brd ff:ff:ff:ff:ff:ff

              And pfSense firewall:

              bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
              options=8009b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,LINKSTATE>
              ether 00:16:17:a7:f2:d3
              hwaddr 00:16:17:a7:f2:d3

              Whether captured on pfSense or desktop computer, the packets between them should show the same MAC addresses. The WAN link will have the pfSense & ISP MACs. The capture I posted about 41 minutes ago was on the LAN side, caputerd in Wireshark on the desktop. The one 4 days ago was on the WAN link, captured with Packet Capture on pfSense. Regardless, whether I have packet captures or not, pfSense is not responding to the traceroute time outs, as I showed with the command line capture earlier. There is only one path from my local network to the Internet and that is via pfSense and cable modem.

              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

                Ok now that we have cleared that up... Are you doing any policy routing? Are you doing any port forwarding... Have you modified any tunables?

                I can not duplicate this problem.. Pfsense should answer these out of the box. So have you tried icmp traceroute?

                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

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

                  @johnpoz said in IPv6 traceroute not showing first hop (pfSense):

                  Ok now that we have cleared that up... Are you doing any policy routing? Are you doing any port forwarding... Have you modified any tunables?

                  No to all the above. Also, given that pfSense is the first hop, why should routing or port forwarding make a difference? An IPv6 packet with a hop limit of 1 should always trigger a TTL timeout without exception.

                  I can not duplicate this problem.. Pfsense should answer these out of the box. So have you tried icmp traceroute?

                  Yes and same thing.

                  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...

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

                    @jknott

                    I've just noticed something else. IPv6 pings to the WAN interface also fail. IPv4 pings do work.

                    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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                    • B
                      bimmerdriver
                      last edited by

                      On my system, for both ipv4 and ipv6, the first hop is my ISP. All hops give an address and most of the will resolve. The result is similar for both udp and icmp.

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                      • JKnottJ
                        JKnott @bimmerdriver
                        last edited by

                        @bimmerdriver said in IPv6 traceroute not showing first hop (pfSense):

                        On my system, for both ipv4 and ipv6, the first hop is my ISP. All hops give an address and most of the will resolve. The result is similar for both udp and icmp.

                        When I do a traceroute, on IPv4, from a computer behind my pfSense firewall, pfSense is the first hop and the first one beyond doesn't show an address. At the moment, there's a problem with my ISP providing IPv6, so I'll have to wait for that to be fixed before seeing what happens with IPv6.

                        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...

                        B 1 Reply Last reply Reply Quote 0
                        • B
                          bimmerdriver @JKnott
                          last edited by

                          @jknott said in IPv6 traceroute not showing first hop (pfSense):

                          @bimmerdriver said in IPv6 traceroute not showing first hop (pfSense):

                          On my system, for both ipv4 and ipv6, the first hop is my ISP. All hops give an address and most of the will resolve. The result is similar for both udp and icmp.

                          When I do a traceroute, on IPv4, from a computer behind my pfSense firewall, pfSense is the first hop and the first one beyond doesn't show an address. At the moment, there's a problem with my ISP providing IPv6, so I'll have to wait for that to be fixed before seeing what happens with IPv6.

                          Very strange. I'm doing the same thing, but getting a different result.

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                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator
                            last edited by

                            So your getting the results I get, where it just works out of the box @bimmerdriver

                            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

                            JKnottJ B 2 Replies Last reply Reply Quote 0
                            • JKnottJ
                              JKnott @johnpoz
                              last edited by

                              @johnpoz said in IPv6 traceroute not showing first hop (pfSense):

                              So your getting the results I get, where it just works out of the box @bimmerdriver

                              It works fine for me on IPv4, but not IPv6. As I mentioned above, my WAN port is not responding to pings on IPv6, but does on IPv4.

                              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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                              • B
                                bimmerdriver @johnpoz
                                last edited by

                                @johnpoz said in IPv6 traceroute not showing first hop (pfSense):

                                So your getting the results I get, where it just works out of the box @bimmerdriver

                                FWIW, I have rule to pass ipv4 and ipv6 echoreq. Nothing else. I get 20/20 on ipv6-test.com (when it works) and 10/10 on test-ipv6.com.

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