Accurate timekeeping is important in networking because accurate time stamps in packets and logs are required.
In Linux operating systems, the NTP protocol is implemented by a daemon running in userspace.
For Fedora distro, you can choose between the daemons
ntpd and
chronyd.
Today I will show you how to use the
chronyd.
The Fedora documentation can be found on
the official website.
Let's install and use this:
[root@desk mythcat]# dnf install chrony
...
[root@desk mythcat]# vim /etc/chrony.conf
With the vim tool now you can add the
In most cases, it's best to use pool.ntp.org to find an NTP server or use servers from your country.
Now, I can start and enable the daemons named
chronyd and add it to the firewall.
[root@desk mythcat]# systemctl start chronyd
[root@desk mythcat]# systemctl status chronyd
● chronyd.service - NTP client/server
Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor p>
Active: active (running) since Sat 2020-08-15 12:23:08 EEST; 9h ago
Docs: man:chronyd(8)
man:chrony.conf(5)
Main PID: 10071 (chronyd)
Tasks: 1 (limit: 11800)
Memory: 1.0M
CPU: 93ms
CGroup: /system.slice/chronyd.service
└─10071 /usr/sbin/chronyd
Aug 15 12:23:08 desk systemd[1]: Starting NTP client/server...
Aug 15 12:23:08 desk chronyd[10071]: chronyd version 3.5 starting (+CMDMON +NTP>
Aug 15 12:23:08 desk chronyd[10071]: Frequency -13.819 +/- 0.344 ppm read from >
Aug 15 12:23:08 desk chronyd[10071]: Using right/UTC timezone to obtain leap se>
Aug 15 12:23:08 desk systemd[1]: Started NTP client/server.
Aug 15 12:23:13 desk chronyd[10071]: Selected source 78.96.7.25
Aug 15 12:23:13 desk chronyd[10071]: System clock TAI offset set to 37 seconds
[root@desk mythcat]# systemctl enable chronyd
[root@desk mythcat]# firewall-cmd --add-service=ntp --permanent
success
[root@desk mythcat]# firewall-cmd --reload
success
You can use it with
chronyc command tool:
[root@desk mythcat]# chronyc sources
210 Number of sources = 4
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^+ blackmamba-g0.eff.ro 3 10 377 692 -1192us[-1273us] +/- 92ms
^+ corporate1.bluepink.ro 2 10 377 200 -1441us[-1441us] +/- 52ms
^+ static-5-2-155-141.rdsne> 2 10 377 468 +1622us[+1540us] +/- 51ms
^* dummy.upcnet.ro 2 10 377 435 -1221us[-1303us] +/- 57ms
[root@desk mythcat]# chronyc tracking
Reference ID : 4E600719 (dummy.upcnet.ro)
Stratum : 3
Ref time (UTC) : Sat Aug 15 19:06:18 2020
System time : 0.000439648 seconds fast of NTP time
Last offset : -0.000081712 seconds
RMS offset : 0.000591977 seconds
Frequency : 13.753 ppm slow
Residual freq : -0.000 ppm
Skew : 0.235 ppm
Root delay : 0.069966756 seconds
Root dispersion : 0.017129980 seconds
Update interval : 1036.2 seconds
Leap status : Normal
[root@desk mythcat]# chronyc activity
200 OK
4 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address