I remember looking at this circa 2016 - 2021 and letting go at that time, crony had just been released and systemd was still relatively new at that time.
/etc/systemd/timesyncd.conf (All the defaults are shown commented out)/etc/systemd/timesyncd.conf to /etc/systemd/timesyncd.conf.d/timesyncd.conf and modify options in /etc/systemd/timesyncd.conf.d/timesyncd.conf
ntp servers can be checked using the ntpdate command, which can be loaded in Debian with sudo apt install ntpsec-ntpdate
Ranked by testing with sudo ntpdate -q {ntp servername/ip}
| sync | accuracy | server | ip address | stratum | leap status |
|---|---|---|---|---|---|
| +0.018040 | +/- 0.026068 | nets.org.sg | 129.126.239.115 | s1 | no-leap |
| +0.020117 | +/- 0.027653 | 3.au.pool.ntp.org | 103.126.53.123 | s2 | no-leap |
| +0.020819 | +/- 0.027315 | 0.au.pool.ntp.org | 139.99.135.247 | s2 | no-leap |
| +0.050351 | +/- 0.064718 | 1.au.pool.ntp.org | 180.150.8.191 | s1 | no-leap |
| +2.023585 | +/- 2.027176 | 2.au.pool.ntp.org | 110.232.114.22 | s2 | no-leap |
Taken 2025-11-09 09:40
| sync | accuracy | server | ip address | stratum | leap status |
|---|---|---|---|---|---|
| +0.002717 | +/- 0.027207 | 3.debian.pool.ntp.org | 139.99.135.247 | s2 | no-leap |
| +0.003344 | +/- 0.030205 | 0.debian.pool.ntp.org | 150.107.75.115 | s2 | no-leap |
| +0.187739 | +/- 0.208642 | 1.debian.pool.ntp.org | 203.132.94.154 | s1 | no-leap |
| +2.001419 | +/- 2.038669 | 2.debian.pool.ntp.org | 159.196.3.239 | s2 | no-leap |
| +0.000044 | +/- 0.024017 | pool.ntp.org | 129.250.35.250 | s2 | no-leap |
| +0.000092 | +/- 0.024373 | au.pool.ntp.org | 112.213.32.219 | s2 | no-leap |
| +0.023537 | +/- 0.064874 | 0.au.pool.ntp.org | 159.196.3.239 | s2 | no-leap |
| +0.000697 | +/- 0.021170 | 1.au.pool.ntp.org | 67.219.100.202 | s2 | no-leap |
| +2.002964 | +/- 2.027214 | 2.au.pool.ntp.org | 112.213.32.219 | s2 | no-leap |
| +0.154351 | +/- 0.184338 | 3.au.pool.ntp.org | 159.196.40.161 | s1 | no-leap |
Taken 2025-11-09 11:15
Based upon the duplication of ip address for different domain names and changing ip addresses on same domain names it looks like the ip address are rolled to different servers to balance load.