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    Unable to access pfsense via serial cable

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

      @Sergei_Shablovsky said in Unable to access pfsense via serial cable:

      Of course, You need additional DB-9 to RJ-45 extender cable.

      Why does he need a DE-9 (yes, that is DE-9, not DB-9) anywhere? He has a USB port on a a computer and that box needs an RJ45, with some serial connection. Hopefully, it will be Cisco compatible, as that is what his cable appears to be.

      I have an adapter with a DE-9 and I then have to use another cable to connect to Cisco gear. I needed a different cable for Adtran and yet another for Ciena. That's what makes this so much "fun".

      However, until the OP contacts the manufacturer to find out what's needed, we are only guessing. As he mentioned, there might also be some configuration needed to even make the console 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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      • jimpJ
        jimp Rebel Alliance Developer Netgate
        last edited by

        Not to mention it may (or may not) need a null modem adapter in the mix depending on the pinout of that port, and depending on the cable connected to that port. Far too many variables that only the OEM (or testing every combination) can verify.

        Remember: Upvote with the 👍 button for any user/post you find to be helpful, informative, or deserving of recognition!

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        • JKnottJ
          JKnott @jimp
          last edited by

          @jimp said in Unable to access pfsense via serial cable:

          need a null modem adapter in the mix depending on the pinout of that port

          Not likely. That's one way things are pretty much standard. The only exception would be on routers, where there's both console and aux ports. The console port connects to a computer and the aux to a modem, for dial in access.

          Incidentally, there's something called a Yost cable, which can be used to connect anything to anything. Cisco is similar to it.

          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...

          Sergei_ShablovskyS jahonixJ 2 Replies Last reply Reply Quote 0
          • Sergei_ShablovskyS
            Sergei_Shablovsky @JKnott
            last edited by

            @JKnott said in Unable to access pfsense via serial cable:

            @jimp said in Unable to access pfsense via serial cable:

            need a null modem adapter in the mix depending on the pinout of that port

            Not likely. That's one way things are pretty much standard. The only exception would be on routers, where there's both console and aux ports. The console port connects to a computer and the aux to a modem, for dial in access.

            Incidentally, there's something called a Yost cable, which can be used to connect anything to anything. Cisco is similar to it.

            Anyway, better to start with something that are standard and working without any problems on most appliances (I mean Prolific :)

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            • DerelictD
              Derelict LAYER 8 Netgate
              last edited by

              Making a serial cable requires the serial pin-outs for that specific port.

              To make a serial connection there you probably only need TXD, RXD, and signal ground - three pins.

              There are 120 combinations of 3 out of the 8 pins in any order so have fun guessing. With a multi-meter or oscilloscope you might be able to eliminate some of those.

              Documented pinouts is far easier.

              If a "cisco" console cable didn't work, the manufacturer needs to provide the pinouts and cable diagrams.

              If they don't have the required documentation, I would return it.

              Bottom line, this is not a problem for the pfSense firewall software to solve.

              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!
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              • jahonixJ
                jahonix @JKnott
                last edited by

                @JKnott said in Unable to access pfsense via serial cable:

                Not likely. That's one way things are pretty much standard. The only exception ...

                I used a KTI industrial switch in the past where TX/RX were reversed as compared to Cisco's pinout. Not funny.

                Just checked, they still do this on current products. From manual:
                Console Port: RS-232, DTE type
                1,2,7,8 NC
                3 RxD IN
                6 TxD OUT
                4,5 GND

                S JKnottJ 2 Replies Last reply Reply Quote 0
                • S
                  smrehan00 @jahonix
                  last edited by

                  @jahonix
                  Thanks guys. I will report back once I achieve connectivity.

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                  • JKnottJ
                    JKnott @jahonix
                    last edited by

                    @jahonix said in Unable to access pfsense via serial cable:

                    I used a KTI industrial switch in the past where TX/RX were reversed as compared to Cisco's pinout. Not funny.

                    I guess I should have clarified a bit more. With serial ports, there is the DCE or modem and DTE or terminal. Those console ports tend to be DCE, with routers having both DCE and DTE ports. The console cable connects to the DCE and a modem connects to the DTE.

                    Regardless, those RJ45 serial ports have no real standard, though those Yost cables are an attempt.

                    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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                    • Sergei_ShablovskyS
                      Sergei_Shablovsky
                      last edited by Sergei_Shablovsky

                      Hi, folks!

                      Please look on whole situation:
                      Operating System -> Device Driver -> USB-2-COM Adapter -> COM port in a target device.

                      On each point possible be fault or wrong working order.
                      So, the solution are simply moving forward from one poling to next to determine what exactly not working well.

                      I just suggest to start from “is my usb-2-com really working” and not wasting time on something other. Another reason are -> many cheaper China-made usb-2-com adapters just piece of crap and not working properly.

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                      • H
                        Heathy65
                        last edited by

                        @smrehan00
                        Hi, did you ever resolve the serial connection issue? I have a MNHO-073 and like you tried a Cisco cable to no avail. Did you ever work out the pinout for the serial RJ45 port?

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                        • stephenw10S
                          stephenw10 Netgate Administrator
                          last edited by

                          @heathy65 said in Unable to access pfsense via serial cable:

                          MNHO-073

                          That device has an hdmi output, does that work as a console?

                          It may have been installed without a serial console enabled, who installed it? What image was used?

                          Steve

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