kazulog@sv1:~$ cat /etc/os-release | head -2
PRETTY_NAME="Ubuntu 26.04 LTS"
NAME="Ubuntu"
kazulog@sv1:~$ ls /etc/chrony/conf.d/ /etc/chrony/sources.d/
/etc/chrony/conf.d/:
README  kazulog-ntp.conf  ubuntu-nts.conf

/etc/chrony/sources.d/:
README  ubuntu-ntp-pools.sources
kazulog@sv1:~$ cat /etc/chrony/conf.d/kazulog-ntp.conf
# 社内 NTP サーバー（R1）を使う
server 192.168.100.1 iburst
kazulog@sv1:~$ chronyc sources -v | tail -8
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^? 192.168.100.1                 3   6    17    34  +1487ms[+1493ms] +/- 1942ms
^+ ntp-nts-2.ps5.canonical.>     2   6    17    39    +11ms[  +17ms] +/-  118ms
^* ntp-nts-3.ps5.canonical.>     2   6    17    38    +14ms[  +21ms] +/-  119ms
^- ntp-nts-2.ps6.canonical.>     2   6    17    38    -41ms[  -41ms] +/-  172ms
^+ ntp-nts-3.ps6.canonical.>     2   6    17    38    -40ms[  -34ms] +/-  168ms
^- ntp-nts-1.ps5.canonical.>     2   6    17    39    +14ms[  +20ms] +/-  120ms
kazulog@sv1:~$ chronyc tracking
Reference ID    : B97DBE7B (ntp-nts-3.ps5.canonical.com)
Stratum         : 3
Ref time (UTC)  : Fri Sep 11 07:26:56 2026
System time     : 0.000006332 seconds slow of NTP time
Last offset     : +0.006336348 seconds
RMS offset      : 0.006336348 seconds
Frequency       : 5.242 ppm fast
Residual freq   : -101.971 ppm
Skew            : 8.059 ppm
Root delay      : 0.237403259 seconds
Root dispersion : 0.007205463 seconds
Update interval : 2.0 seconds
Leap status     : Normal