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    SG-3100 switch weird behavior (resolved)

    Scheduled Pinned Locked Moved Official Netgate® Hardware
    sg-3100switcharpsyslog
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    • M
      mcury @johnpoz
      last edited by

      @johnpoz Exactly, its so weird, that packet should never go to pfsense's LAN1 ..

      I'll try to fix it tonight by reinstalling my pfsense from scratch..
      Then, if the problem happens again, I'll replace this switch..

      dead on arrival, nowhere to be found.

      1 Reply Last reply Reply Quote 0
      • stephenw10S
        stephenw10 Netgate Administrator
        last edited by

        Yeah, it's a pretty basic switch and there's no control over things like the MAC table. That's the only thing I could imagine causing that though.

        If you haven't already try power cycling the 3100 entirely. That should completely reset the switch if it's somehow managed to toggle some flag.

        Steve

        M 1 Reply Last reply Reply Quote 0
        • M
          mcury @stephenw10
          last edited by

          @stephenw10 hm, I'll try it now a shutdown, remove the power cable, one sec, let me see who is here using the Internet

          dead on arrival, nowhere to be found.

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

            Done, the problem persists..

            1. Halt system and once the shutdown process ended, removed the power cable for a few seconds.

            0c31ac53-951d-4c89-89a8-4fadaed63ab6-image.png

            6910718c-7557-49a5-918d-8e19068f4198-image.png

            dead on arrival, nowhere to be found.

            1 Reply Last reply Reply Quote 0
            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by stephenw10

              Hmm, the only other thing I could imagine causing this is if something feeding bad data into the switch MAC table. That would have to be the desktop machine.

              If you run a continuous ping from the RasPi to somewhere that has to be accessed through the 3100 switch, does that prevent the issue?

              If it does I'd try to find something sending the RasPi MAC from the desktop. Hard to say what that might be.... something reflected perhaps?

              If you run a pcap on the desktop and filter by the RasPi MAC address whilst the problem is not happening and wait for it to start. The first thing that happens there might be the offending packet.

              Steve

              M 1 Reply Last reply Reply Quote 0
              • M
                mcury @stephenw10
                last edited by mcury

                @stephenw10 said in SG-3100 switch weird behavior:

                If you run a continuous ping from the RasPi to somewhere that has to be accessed through the 3100 switch, does that prevent the issue?

                Testing now, ping is running from RPI4 to pfsense.
                It seems to have stopped, but it may start again soon, so I'll wait a little longer this time.

                Packet capture set:
                a0a5c924-fc4a-43f3-9466-2aa3c860e74e-image.png

                Edit:

                This is my ARP table (desktop)

                $ cat /proc/net/arp
                IP address       HW type     Flags       HW address            Mask     Device
                192.168.255.252  0x1         0x2         00:11:32:9f:ee:93     *        enp7s0
                192.168.255.249  0x1         0x2         00:08:a2:0c:c4:1c     *        enp7s0
                192.168.255.250  0x1         0x2         b8:27:eb:ea:f8:65     *        enp7s0
                192.168.255.253  0x1         0x2         dc:a6:32:a5:47:19     *        enp7s0
                

                dead on arrival, nowhere to be found.

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

                  40 minutes pinging from raspberry pi 4b (192.168.255.253) to pfsense (192.168.255.249) and no problem so far.

                  I have two wireshark windows opened, one monitoring:
                  eth.src == dc:a6:32:a5:47:19 and not tcp.port == 22 and not tcp.port == 9000

                  And the second one monitoring:
                  ip.addr == 192.168.255.253 and not tcp.port == 9000 and not tcp.port == 22

                  dead on arrival, nowhere to be found.

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

                    Dropped the ping and one minute later (or less), the problem starts again:

                    84f90579-b4d5-4df7-b823-f091eb706d61-image.png

                    desktop ARP table:
                    $ cat /proc/net/arp
                    IP address HW type Flags HW address Mask Device
                    192.168.255.252 0x1 0x2 00:11:32:9f:ee:93 * enp7s0
                    192.168.255.249 0x1 0x2 00:08:a2:0c:c4:1c * enp7s0
                    192.168.255.250 0x1 0x2 b8:27:eb:ea:f8:65 * enp7s0
                    192.168.255.253 0x1 0x2 dc:a6:32:a5:47:19 * enp7s0

                    dead on arrival, nowhere to be found.

                    1 Reply Last reply Reply Quote 0
                    • stephenw10S
                      stephenw10 Netgate Administrator
                      last edited by

                      Hmm, so nothing from the RasPi MAC address at the desktop that might be inserting invalid entries into the switch.

                      It might be worth re-running that test using the RasPi MAC as destination in the filter (or as either).
                      You might catch something arriving using that but a different IP address.

                      Also when this happens do you see traffic being sent only to the desktop? Or is the syslog traffic sent to all the 3100 switch ports? Does it also arrive at the RasPi?

                      Steve

                      M 1 Reply Last reply Reply Quote 0
                      • M
                        mcury @stephenw10
                        last edited by

                        @stephenw10 It seems that its only going to LAN1..

                        d6978265-5e91-4305-bf2d-0c79ff092142-image.png

                        raspberry pi 3 in which you see the tcpdump above is connected to the switch unifi mini.

                        Let me perform this test again, but in the NAS which is connected to LAN2 of pfsense, one sec.

                        dead on arrival, nowhere to be found.

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

                          Hmmm, its going to port LAN2 of pfsense too:
                          NAS IP is 192.168.255.252 (tcpdump) (LAN2 of pfsense)

                          On the right, wireshark running on desktop (LAN1 of pfsense)

                          9b27a73e-270d-451c-88e1-ea4b7c604009-image.png

                          dead on arrival, nowhere to be found.

                          1 Reply Last reply Reply Quote 0
                          • stephenw10S
                            stephenw10 Netgate Administrator
                            last edited by

                            Aha, interesting. You wouldn't expect so see it on one of the other Unifi swtch ports because it should only send it out of the port that MAC is connected to. So to the RasPi4 there.

                            The same should be true of the switch in the 3100 The fact it seems to be sending it to all ports implies that it no longer has a an entry for the MAC address in it's table. If it was an incorrect entry as I speculated earlier then it would only send from port 1.
                            Because that traffic is UDP with no replies it never sees any traffic from the RasPi4 to repopulate the table. Is the RasPi configured with a static IP?

                            It seems unexpected that the table entry has expired though. How long does it take to fail after sending some pings approximately?

                            Steve

                            johnpozJ M 2 Replies Last reply Reply Quote 0
                            • johnpozJ
                              johnpoz LAYER 8 Global Moderator @stephenw10
                              last edited by

                              @stephenw10 said in SG-3100 switch weird behavior:

                              How long does it take to fail after sending some pings approximately?

                              the default cache in pfsense is like 20 minutes, but maybe not for the switch mac table? Is there anyway to view the switches mac address table?

                              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
                                mcury @stephenw10
                                last edited by

                                @stephenw10 said in SG-3100 switch weird behavior:

                                Because that traffic is UDP with no replies it never sees any traffic from the RasPi4 to repopulate the table. Is the RasPi configured with a static IP?

                                raspberry pi 4b its on dhcp, no services running on it, only graylog, which means that the device only receives UDP data.

                                It seems unexpected that the table entry has expired though. How long does it take to fail after sending some pings approximately?

                                I'll try to get that info right now.

                                dead on arrival, nowhere to be found.

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

                                  @johnpoz said in SG-3100 switch weird behavior:

                                  the default cache in pfsense is like 20 minutes, but maybe not for the switch mac table? Is there anyway to view the switches mac address table?

                                  I'm really missing my old Cisco days, show mac-address table vlan x :)

                                  dead on arrival, nowhere to be found.

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

                                    @mcury hehe - yeah would be easy to see then.. Why I like my routers with interfaces, leave the switch ports to the actual switches ;)

                                    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 1
                                    • M
                                      mcury @johnpoz
                                      last edited by

                                      @johnpoz said in SG-3100 switch weird behavior:

                                      @mcury hehe - yeah would be easy to see then.. Why I like my routers with interfaces, leave the switch ports to the actual switches ;)

                                      :) Yes, you have a point there ehhe

                                      tcpdump in pfsense during the DHCP negotiation with raspberry pi 4b

                                      593529d9-b4bd-4207-b57d-99248f0dc9c8-image.png

                                      f2d379a3-e181-4362-b519-7fb40ba9a350-image.png

                                      dead on arrival, nowhere to be found.

                                      1 Reply Last reply Reply Quote 0
                                      • stephenw10S
                                        stephenw10 Netgate Administrator
                                        last edited by

                                        Yeah the pfSense ARP cache expiry time is completely independent of the switch MAC table. I don't believe there's any way to query the switch IC for the table or for the expiry time.

                                        Steve

                                        M 1 Reply Last reply Reply Quote 0
                                        • M
                                          mcury @stephenw10
                                          last edited by

                                          @stephenw10 said in SG-3100 switch weird behavior:

                                          Yeah the pfSense ARP cache expiry time is completely independent of the switch MAC table. I don't believe there's any way to query the switch IC for the table or for the expiry time.

                                          Steve

                                          3 minutes exactly.

                                          dead on arrival, nowhere to be found.

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

                                            I recorded, not sure if its going to be useful..
                                            arp_problem.zip

                                            dead on arrival, nowhere to be found.

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