Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    Building a Stratum 1 NTP Server Using Odroid C2

    Scheduled Pinned Locked Moved Off-Topic & Non-Support Discussion
    45 Posts 4 Posters 8.6k Views 3 Watching
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • J Offline
      jcpingu @stephenw10
      last edited by

      @stephenw10

      It shows:
      fb2d9cf0-26b6-4084-bdeb-c0e55d5864f8-image.png

      J 1 Reply Last reply Reply Quote 0
      • J Offline
        jcpingu @jcpingu
        last edited by

        @jcpingu
        I followed this guide:
        https://nguvu.org/pfsense/network%20time%20protocol%20(ntp)/ntp-server/
        Your output looks different than mine. Again, I am not a linux guy so there are things that may not be in the guide that I am missing...

        1 Reply Last reply Reply Quote 0
        • bingo600B Offline
          bingo600
          last edited by bingo600

          NTP will exit or refuse to start if the local clock is too far off the NTP received clock. ISTR 15 sec is the limit.

          Most installations uses ntpdate , to update the local clock before starting the NTP daemon.

          https://linux.die.net/man/8/ntpdate

          Remember once the NTP daemon is started , ntpdate won't connect anymore.
          As the daemon "owns/blocks" the port.

          Edit:
          Now will be a good time to reveal what Linux distro you have installed on the C2 ....

          Edit2:
          Wasn't this a Stratum 1 server build ... Indicating you have a GPS clock source ?
          Then the NTP date shouldn't be needed , provided your GPS sends the correct data sentences.

          /Bingo

          If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

          pfSense+ 23.05.1 (ZFS)

          QOTOM-Q355G4 Quad Lan.
          CPUĀ  : Core i5 5250U, Ram : 8GB Kingston DDR3LV 1600
          LANĀ  : 4 x Intel 211, DiskĀ  : 240G SAMSUNG MZ7L3240HCHQ SSD

          J 1 Reply Last reply Reply Quote 1
          • J Offline
            jcpingu @bingo600
            last edited by

            @bingo600

            I am using dietpi 7.2

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

              Yes, it's showing 0 reach there so it's not seeing any data. Also no other ntp servers configured as sources so it's never going to sync to anything.

              Is your GPS seeing sufficient satellites to get a lock?

              Are you seeing NMEA strings from it on the com port?

              My output looks different to yours because I'm running that on pfSense directly.

              Steve

              J 2 Replies Last reply Reply Quote 0
              • J Offline
                jcpingu @stephenw10
                last edited by

                @stephenw10
                edcf6868-effc-4e2b-a535-9cf31ec3d958-image.png

                bingo600B 1 Reply Last reply Reply Quote 0
                • J Offline
                  jcpingu @stephenw10
                  last edited by

                  @stephenw10
                  b0ba5f8a-3265-48e6-a52c-48fded7fa7f1-image.png

                  1 Reply Last reply Reply Quote 0
                  • bingo600B Offline
                    bingo600 @jcpingu
                    last edited by bingo600

                    @jcpingu
                    The interesting NMEA packets are the : $GNRMC packets.

                    I see you skipped the "NMEA" filter the guide uses (to only see the RMC's) , was that because you don't use an Ublox 8 ?

                    Edit:
                    From the guide:
                    Uses the NMEA reference clock 20 driver specified by 127.127.20.0.
                    Mode 17 sets the driver to process only GPRMC message at 9600bps. Using higher clock speeds does not necessarily increase timing precision and because we have disabled non-GPRMC messages, there’s no risk of not being able to transmit the message within the 1 second timespan.

                    Did i see you use 115200 ???

                    /Bingo

                    If you find my answer useful - Please give the post a šŸ‘ - "thumbs up"

                    pfSense+ 23.05.1 (ZFS)

                    QOTOM-Q355G4 Quad Lan.
                    CPUĀ  : Core i5 5250U, Ram : 8GB Kingston DDR3LV 1600
                    LANĀ  : 4 x Intel 211, DiskĀ  : 240G SAMSUNG MZ7L3240HCHQ SSD

                    J 3 Replies Last reply Reply Quote 0
                    • J Offline
                      jcpingu @bingo600
                      last edited by

                      @bingo600
                      I have a newer revision of the GPS Board. Its default baud is 115200

                      1 Reply Last reply Reply Quote 0
                      • J Offline
                        jcpingu @bingo600
                        last edited by

                        @bingo600
                        I will check $GNRMC. It looks like I am not getting them...

                        1 Reply Last reply Reply Quote 0
                        • J Offline
                          jcpingu @bingo600
                          last edited by

                          @bingo600
                          Here you go:
                          95285b07-d93b-4144-a19c-448d783c8259-image.png

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

                            Does ppstest work against gpspps0? If not did you create the symlink?

                            What does your ntp.conf file look like? Did you change the mode for 115200 baud?

                            Edit: Yeah you probably want mode 81 there.

                            Steve

                            J 2 Replies Last reply Reply Quote 0
                            • J Offline
                              jcpingu @stephenw10
                              last edited by

                              @stephenw10
                              Yes per the guide Symlink is used, there's a file that use the below:
                              KERNEL=="ttyS1", SYMLINK+="gps0"
                              KERNEL=="pps0", SYMLINK+="gpspps0"

                              Also, how do I edit ntp.conf? When I enter it, I get permission denied
                              79f235ba-6626-432e-acc8-b2f19fe3c546-image.png

                              1 Reply Last reply Reply Quote 0
                              • J Offline
                                jcpingu @stephenw10
                                last edited by jcpingu

                                @stephenw10
                                Here is the ntp.conf content in the guide. Are you saying to change mode 17 to 81?

                                server 127.127.20.0 mode 17 minpoll 4 maxpoll 4 prefer
                                fudge 127.127.20.0 flag1 1 refid GPS

                                security

                                restrict default kod limited nomodify nopeer
                                restrict -6 default kod limited nomodify nopeer

                                Local users may interrogate the NTP server fully.

                                restrict 127.0.0.1
                                restrict -6 ::1

                                stats

                                driftfile /var/lib/ntp/ntp.drift

                                Enable statistics logging.

                                statsdir /var/log/ntpstats/
                                statistics loopstats peerstats clockstats
                                filegen loopstats file loopstats type day enable
                                filegen peerstats file peerstats type day enable
                                filegen clockstats file clockstats type day enable

                                leap file

                                leapfile /var/lib/ntp/leap-seconds.list

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

                                  Yes because, like it says there, mode 17 is for 9600 baud and your GPS is running at 115200. So currently it's seeing no data.

                                  J 3 Replies Last reply Reply Quote 1
                                  • J Offline
                                    jcpingu @stephenw10
                                    last edited by

                                    @stephenw10
                                    Thank you. I will advise latest status...

                                    1 Reply Last reply Reply Quote 0
                                    • J Offline
                                      jcpingu @stephenw10
                                      last edited by

                                      @stephenw10
                                      The good News:
                                      b022b744-34df-44b1-b57b-6840e82c4dca-image.png

                                      The not so good news, I am still seeing clock unsynchronized:
                                      6f2be03c-eca7-445a-811f-dfa31af4a896-image.png

                                      1 Reply Last reply Reply Quote 0
                                      • J Offline
                                        jcpingu @stephenw10
                                        last edited by

                                        @stephenw10
                                        I was looking @ your example, and I see that it also shows this error:
                                        Jun 21 18:35:03 ntpd 56634 kernel reports TIME_ERROR: 0x41: Clock Unsynchronized

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

                                          Yes, I expect it to show that when ntpd is first started. It won't sync until sometime later when ntp is confident the time data it has is correct.
                                          Wait some time and recheck. Or it may have already sync'd there since it show an offset or effectively 0 (2μs) from the GPS time.

                                          Steve

                                          J 2 Replies Last reply Reply Quote 1
                                          • J Offline
                                            jcpingu @stephenw10
                                            last edited by

                                            @stephenw10
                                            Thank you for all your help. I truly appreciate your patience and kindness. I still see the error this morning. However ntpq -p is showing the right output. I am assuming there's nothing I can do about the error...
                                            f64cc788-75d7-4e80-b6de-1709d5f94363-image.png

                                            bingo600B 2 Replies Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.