• Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Search
  • Register
  • Login
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 6.9k Views
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
    jcpingu @stephenw10
    last edited by Jun 21, 2021, 7:00 PM

    @stephenw10

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

    J 1 Reply Last reply Jun 21, 2021, 7:07 PM Reply Quote 0
    • J
      jcpingu @jcpingu
      last edited by Jun 21, 2021, 7:07 PM

      @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
      • B
        bingo600
        last edited by bingo600 Jun 21, 2021, 7:18 PM Jun 21, 2021, 7:13 PM

        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 👍 - "thumbs up"

        pfSense+ 23.05.1 (ZFS)

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

        J 1 Reply Last reply Jun 21, 2021, 8:10 PM Reply Quote 1
        • J
          jcpingu @bingo600
          last edited by Jun 21, 2021, 8:10 PM

          @bingo600

          I am using dietpi 7.2

          1 Reply Last reply Reply Quote 0
          • S
            stephenw10 Netgate Administrator
            last edited by Jun 21, 2021, 8:27 PM

            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 Jun 21, 2021, 8:32 PM Reply Quote 0
            • J
              jcpingu @stephenw10
              last edited by Jun 21, 2021, 8:32 PM

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

              B 1 Reply Last reply Jun 21, 2021, 8:58 PM Reply Quote 0
              • J
                jcpingu @stephenw10
                last edited by Jun 21, 2021, 8:36 PM

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

                1 Reply Last reply Reply Quote 0
                • B
                  bingo600 @jcpingu
                  last edited by bingo600 Jun 21, 2021, 9:00 PM Jun 21, 2021, 8:58 PM

                  @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 👍 - "thumbs up"

                  pfSense+ 23.05.1 (ZFS)

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

                  J 3 Replies Last reply Jun 21, 2021, 9:06 PM Reply Quote 0
                  • J
                    jcpingu @bingo600
                    last edited by Jun 21, 2021, 9:06 PM

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

                    1 Reply Last reply Reply Quote 0
                    • J
                      jcpingu @bingo600
                      last edited by Jun 21, 2021, 9:11 PM

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

                      1 Reply Last reply Reply Quote 0
                      • J
                        jcpingu @bingo600
                        last edited by Jun 21, 2021, 9:23 PM

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

                        1 Reply Last reply Reply Quote 0
                        • S
                          stephenw10 Netgate Administrator
                          last edited by stephenw10 Jun 21, 2021, 9:57 PM Jun 21, 2021, 9:51 PM

                          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 Jun 21, 2021, 10:15 PM Reply Quote 0
                          • J
                            jcpingu @stephenw10
                            last edited by Jun 21, 2021, 10:15 PM

                            @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
                              jcpingu @stephenw10
                              last edited by jcpingu Jun 21, 2021, 10:23 PM Jun 21, 2021, 10:22 PM

                              @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
                              • S
                                stephenw10 Netgate Administrator
                                last edited by Jun 21, 2021, 11:22 PM

                                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 Jun 22, 2021, 1:48 AM Reply Quote 1
                                • J
                                  jcpingu @stephenw10
                                  last edited by Jun 22, 2021, 1:48 AM

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

                                  1 Reply Last reply Reply Quote 0
                                  • J
                                    jcpingu @stephenw10
                                    last edited by Jun 22, 2021, 2:09 AM

                                    @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
                                      jcpingu @stephenw10
                                      last edited by Jun 22, 2021, 2:55 AM

                                      @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
                                      • S
                                        stephenw10 Netgate Administrator
                                        last edited by Jun 22, 2021, 10:49 AM

                                        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 Jun 22, 2021, 3:57 PM Reply Quote 1
                                        • J
                                          jcpingu @stephenw10
                                          last edited by Jun 22, 2021, 3:57 PM

                                          @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

                                          B 2 Replies Last reply Jun 22, 2021, 4:46 PM Reply Quote 0
                                          21 out of 45
                                          • First post
                                            21/45
                                            Last post
                                          Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.
                                            This community forum collects and processes your personal information.
                                            consent.not_received