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FYI: Ipv6 users should use 2.pool.ntp.org as their NTP server

Scheduled Pinned Locked Moved IPv6
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  • I
    IsaacFL
    last edited by Mar 10, 2019, 6:29 PM

    For those who have ipv6 and want to use pool.ntp.org as the time server for your NTP clients, they should use 2.pool.ntp.org as this is the only one that returns both A and AAAA records for NTP servers. pool.ntp.org is ipv4 only and many people by default use pool.ntp.org

    This also works for regional servers. i.e I am in the US so I use 2.us.pool.ntp.org. It also works for the distro specific entries like 2.pfsense.pool.ntp.org and 2.fedora.pool.ntp.org. Only 2 returns v6 entries.

    S 1 Reply Last reply Apr 24, 2023, 3:35 PM Reply Quote 3
    • S
      Sergei_Shablovsky @IsaacFL
      last edited by Apr 24, 2023, 3:35 PM

      @isaacfl What is situation on Apr 2023 with this?

      I mean is there are new NTP pools with AAAA added, or old reconfigured ?

      And another question how You check ability of servers/pools to correctly working with ipv6 clients?

      Thanks!

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      J 1 Reply Last reply Apr 24, 2023, 3:50 PM Reply Quote 0
      • J
        johnpoz LAYER 8 Global Moderator @Sergei_Shablovsky
        last edited by johnpoz Apr 24, 2023, 3:54 PM Apr 24, 2023, 3:50 PM

        @sergei_shablovsky I think 2.xxxx the only pools that have AAAA entries..

        Be it country, or zone based like north-america or africa, asia, etc.. Or vendor specific like 2.pfsense.ntp

        NTP suggests that if your a vendor that will be setting up ntp on the devices you sell/distribute that you register your own vendor name for the zones, etc. Lets say it is stronger than a suggestion ;)

        "You must absolutely not use the default pool.ntp.org zone names as the default configuration in your application or appliance. "

        Now what a user changes ntp to use after they set it up, would not be the vendors problem - but ntp is pretty against vendors shipping their stuff with the default pool names..

        https://www.ntppool.org/en/vendors.html

        But I believe only ones that start with 2 have IPv6, all the other 0, 1 and 3 only have IPv4

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        1 Reply Last reply Reply Quote 1
        • M
          maverickws
          last edited by Apr 28, 2023, 10:41 AM

          I use time.apple.com and time.euro.apple.com both pools and IPv6 enabled for idk maybe over a decade?

          D 1 Reply Last reply Jun 2, 2023, 5:02 AM Reply Quote 0
          • C
            compuguy
            last edited by May 1, 2023, 4:37 PM

            You can add time.nist.gov as a ntp host/pool that returns a AAAA record to the list as well.

            R 1 Reply Last reply May 2, 2023, 1:20 PM Reply Quote 2
            • R
              RobbieTT @compuguy
              last edited by May 2, 2023, 1:20 PM

              The 'teaching' back in the day was to use real v4 or v6 addresses as part of the mix to ensure that a DNS failure would not interrupt NTP.

              The NTP pools discouraged that these days but old habits and logic die hard.

              ☕️

              1 Reply Last reply Reply Quote 0
              • J
                JKnott
                last edited by May 2, 2023, 1:37 PM

                I use 3 stratum 1 servers from a local Internet exchange, along with 2 stratum 2 from the Canadian government and time.google.com. The 3 Internet exchange servers and Google have both IPv4 and IPv6 addresses available.

                The University of Toronto has two NTP servers, tick & tock. 😉

                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...

                R 1 Reply Last reply May 2, 2023, 2:05 PM Reply Quote 0
                • R
                  RobbieTT @JKnott
                  last edited by RobbieTT May 2, 2023, 2:29 PM May 2, 2023, 2:05 PM

                  @jknott

                  I like to have a stratum 1 on the LAN side, as part of the wider mix:

                   2023-05-02 at 15.26.45.png

                  ☕️

                  J 1 Reply Last reply May 2, 2023, 4:37 PM Reply Quote 0
                  • J
                    JKnott @RobbieTT
                    last edited by May 2, 2023, 4:37 PM

                    @robbiett

                    Unfortunately, many of us don't have a stratum 0 source. My LAN sees a stratum 2 server.

                    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...

                    1 Reply Last reply Reply Quote 0
                    • D
                      darkonc @maverickws
                      last edited by Jun 2, 2023, 5:02 AM

                      @maverickws That's no big surprise. The 2.* rule is for 2.*.pool.ntp.org . Other organizations / domains can do whatever they want.

                      M 1 Reply Last reply Jun 15, 2023, 9:46 AM Reply Quote 0
                      • M
                        maverickws @darkonc
                        last edited by Jun 15, 2023, 9:46 AM

                        @darkonc was that for me?

                        1 Reply Last reply Reply Quote 0
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