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    pfSense Rewrites Source IP for ICMP Errors Breaking Traceroute

    Scheduled Pinned Locked Moved General pfSense Questions
    icmptraceroutenat
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    • johnpozJ
      johnpoz LAYER 8 Global Moderator
      last edited by

      So yes the nat would send the traffic back into your sender of the traceroute.. So I am just thinking you are confused to how nat works in general... But seeing missing spots in your trace that do not answer is quite normal these days of everyone blocking shit ;)

      Are you doing anything odd on your lan side interface for rules or policy routing?

      I sure an the hell can not duplicate your issue, and can traceroute from any machine on my network just fine using either icmp, udp or even tcp...

      $ tcptraceroute -n www.google.com 443
      Selected device ens3, address 192.168.2.12, port 50519 for outgoing packets
      Tracing the path to www.google.com (172.217.8.196) on TCP port 443 (https), 30 hops max
       1  192.168.2.253  0.493 ms  0.332 ms  0.324 ms
       2  50.4.135.1  11.620 ms  12.213 ms  11.700 ms
       3  76.73.191.106  10.921 ms  12.476 ms  11.911 ms
       4  76.73.164.142  9.586 ms  18.234 ms  12.953 ms
       5  76.73.164.154  20.807 ms  20.399 ms  20.238 ms
       6  76.73.191.242  14.286 ms  11.709 ms  14.869 ms
       7  143.59.95.224  28.425 ms  12.980 ms  13.262 ms
       8  75.76.35.8  11.605 ms  22.702 ms  10.050 ms
       9  72.14.211.145  11.355 ms  31.802 ms  18.859 ms
      10  108.170.243.225  23.928 ms  13.804 ms  14.214 ms
      11  72.14.232.187  12.821 ms  12.967 ms  13.243 ms
      12  172.217.8.196 [open]  21.723 ms  31.557 ms  17.055 ms
      

      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

      1 Reply Last reply Reply Quote 0
      • M
        miki725
        last edited by

        Didnt do anything crazy as far as I know:

        fd42625e-ec02-4575-b93d-e0c225c71fee-image.png

        Ill keep digging on my end. Thanks for your help.

        A 1 Reply Last reply Reply Quote 0
        • A
          Alex Atkin UK @miki725
          last edited by

          @miki725 Is it the same problem documented here? https://redmine.pfsense.org/issues/9263

          M 1 Reply Last reply Reply Quote 1
          • GertjanG
            Gertjan
            last edited by

            You're using traffic (ICMP) shaping ?

            No "help me" PM's please. Use the forum, the community will thank you.
            Edit : and where are the logs ??

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

              Sure looks like that is his problem... @Alex-Atkin-UK

              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

              1 Reply Last reply Reply Quote 0
              • M
                miki725 @Alex Atkin UK
                last edited by

                @Alex-Atkin-UK

                ooooh. I forgot about the limiter:

                d8918570-58cb-43e5-a943-7dfd6d5a99ca-image.png

                can confirm that when I disabled floating rule with the queue, traceroute works as expected inside LAN.

                Thank a lot for linking to that. Now would be curious why a limiter would have that affect.

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

                  @miki725 said in pfSense Rewrites Source IP for ICMP Errors Breaking Traceroute:

                  Now would be curious why a limiter would have that affect.

                  It shouldn't - therefore the bug report ;)

                  You should of brought up the limiter, when asked doing anything odd on lan side rules (floating would be considered lan side) hehehe.. I will make sure to always mention floating rules going forward..

                  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

                  M 1 Reply Last reply Reply Quote 0
                  • M
                    miki725 @johnpoz
                    last edited by

                    @johnpoz said in pfSense Rewrites Source IP for ICMP Errors Breaking Traceroute:

                    You should of brought up the limiter, when asked doing anything odd on lan side rules (floating would be considered lan side) hehehe.. I will make sure to always mention floating rules going forward..

                    My apologies. Forgot about them. Makes perfect sense that they are as legitimate LAN side rule as any other.

                    Thanks everyone for helping even with limited provided information. Really appreciate everyones time and effort. Stay safe!

                    A 1 Reply Last reply Reply Quote 0
                    • A
                      Alex Atkin UK @miki725
                      last edited by Alex Atkin UK

                      @miki725 I remembered it as I had the same problem.

                      As I recall you have to add a Pass floating rule for the WAN interface at the top of the list for echo reply/requests with Quick ticked, so it bypasses the limiter rule.

                      1 Reply Last reply Reply Quote 0
                      • GertjanG
                        Gertjan
                        last edited by Gertjan

                        @Alex-Atkin-UK : Thanks.

                        That were those for :

                        1b20b041-6cb8-43d4-8451-16f015d4f5a0-image.png

                        ( bottom two rules )

                        No "help me" PM's please. Use the forum, the community will thank you.
                        Edit : and where are the logs ??

                        1 Reply Last reply Reply Quote 0
                        • M
                          miki725
                          last edited by

                          Thanks for the suggestion. Didnt even think of bypassing it.

                          Where is a standard place to add limiter rules? Mine is currently is a floating rule. Even with the ICMP bypass rule with Quick above it, traceroute is still impacted:

                          e1a36188-e928-4cd2-8906-4b18b6976bc2-image.png

                          I tried removing the Quick from the limiter rule but that does not seem to help. Only thing which helps is disabling the limiter altogether. Im probably not doing something correctly if this works for you.

                          1 Reply Last reply Reply Quote 1
                          • GertjanG
                            Gertjan
                            last edited by

                            Like me, you added floating rules to do something about buffer bloat.

                            These are all my floating rules :

                            bf4bc721-c6d5-485e-9c04-57ccd1ca8c31-image.png

                            You're missing one IPv4 rule : the "direction : IN" rule.
                            You have the "Out" rule, the one with the gateway (WAN_DHCP).

                            I also use IPv6 - so that adds 3 more rules.

                            No "help me" PM's please. Use the forum, the community will thank you.
                            Edit : and where are the logs ??

                            1 Reply Last reply Reply Quote 0
                            • B
                              bobbenheim
                              last edited by

                              In your ICMP rule setting direction: out, interface: WAN and change default to your actual gateway in advanced > Gateway
                              should do the job.

                              1 Reply Last reply Reply Quote 0
                              • J
                                jamesonp
                                last edited by

                                This got me today. I can confirm the floating rule for ICMP solves the issue.

                                1 Reply Last reply Reply Quote 0
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