"system clock synchronized: no", flip it to yes

Question

# timedatectl outputs

               Local time: Tue 2020-10-06 13:35:31 PDT
           Universal time: Tue 2020-10-06 20:35:31 UTC
                 RTC time: Tue 2020-10-06 20:35:30
                Time zone: America/Los_Angeles (PDT, -0700)
System clock synchronized: no
              NTP service: active
          RTC in local TZ: no

/etc/chrony.conf is the default in RHEL 8 (with a preconfigured pool).

# chronyc sources outputs

210 Number of sources = 8
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^? excalibur.prolixium.com       0   9     0     -     +0ns[   +0ns] +/-    0ns
^? paladin.latt.net              0   9     0     -     +0ns[   +0ns] +/-    0ns
^? ronin.ruselabs.com            0   9     0     -     +0ns[   +0ns] +/-    0ns
^? 2a00:7600::41                 0   9     0     -     +0ns[   +0ns] +/-    0ns
^? 50-205-244-112-static.hf>     0   9     0     -     +0ns[   +0ns] +/-    0ns
^? time.cloudflare.com           0   9     0     -     +0ns[   +0ns] +/-    0ns
^? 69.10.161.7                   0   9     0     -     +0ns[   +0ns] +/-    0ns
^? ntp3.your.org                 0   9     0     -     +0ns[   +0ns] +/-    0ns

# systemctl status chronyd shows active (running), and no errors in the logs.

The displayed system time is correct.

So, given all these facts, why is it that I see System clock synchronized: no? How do I turn it to yes?

And why do I see stratum 0 in `# chronyc sources`? Also `# chronyc tracking` gives stratum 0. — Katerl3s, Oct 06 '20 at 21:06

score 3 · Accepted Answer · answered Oct 06 '20 at 22:26

3

chronyc sources indicates that it does not have connectivity to any of the available NTP servers. This is what the ? in the S column means, from the man page:

This column indicates the state of the source.

? indicates sources to which connectivity has been lost or whose packets do not pass all tests. It is also shown at start-up, until at least 3 samples have been gathered from it.

Check your Internet connectivity, host firewall, external firewalls, etc.

answered Oct 06 '20 at 22:26

Michael Hampton

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In fact, this is a playground server behind a NAT that doesn't allow port 123/udp in either direction. – Katerl3s Oct 06 '20 at 22:40
And that's why you can't synchronize. – Michael Hampton Oct 06 '20 at 22:58
I'm now trying to synchronize 2 machines in the playground that I know can ping to each other and I just added the ntp service to their firewalld and designated one the source to the other. If it was just a connectivity issue, this should work – Katerl3s Oct 06 '20 at 23:06
yup. ? changes to * and no changes to yes. – Katerl3s Oct 06 '20 at 23:09

"system clock synchronized: no", flip it to yes

1 Answers1