{"id":7162,"date":"2020-10-21T21:57:52","date_gmt":"2020-10-21T18:57:52","guid":{"rendered":"https:\/\/kifarunix.com\/?p=7162"},"modified":"2024-03-14T23:25:16","modified_gmt":"2024-03-14T20:25:16","slug":"quickly-setup-ntp-server-using-ntpd-on-ubuntu-20-04-18-04","status":"publish","type":"post","link":"https:\/\/kifarunix.com\/quickly-setup-ntp-server-using-ntpd-on-ubuntu-20-04-18-04\/","title":{"rendered":"Quickly Setup NTP Server using NTPd on Ubuntu 20.04\/18.04"},"content":{"rendered":"\n

In this tutorial, you will learn how to install and setup NTP server using NTPd on Ubuntu 20.04\/18.04. Network Time Protocol<\/a> is a networking protocol that is used to synchronize system clocks on a network. NTP uses clock stratum scheme to enable access to correct time sources. The stratums<\/em> are numbered from 0 to 15, where the devices at stratum 0 are highly accurate time-keeping hardware devices and the latter is true. The stratums<\/em> usually have NTP clients. An NTP client can also be configured as a server in a customized environment.<\/p>\n\n\n\n

NTP client employs a server-client architecture where NTP clients synchronize time from NTP server(s).<\/p>\n\n\n\n

Installing NTP Server using NTPd on Ubuntu 20.04\/18.04<\/h2>\n\n\n\n

Run System Update<\/h3>\n\n\n\n

Before you can install and setup NTP Server, you need to update your package cache in order to install the latest version of ntp<\/em>.<\/p>\n\n\n\n

sudo apt update -y<\/code><\/pre>\n\n\n\n
Install NTPd on Ubuntu 20.04\/18.04<\/h3>\n\n\n\n
Once the update is done, proceed to install NTP daemon on Ubuntu 20.04\/18.04. The ntpd daemon is provided by the ntp<\/em> package.<\/p>\n\n\n\n
To check if ntp<\/em> package is installed on Ubuntu 18.04\/20.04 run the command:<\/p>\n\n\n\n
 dpkg -l ntp<\/code><\/pre>\n\n\n\n
If the package is not installed you will get output similar to:<\/p>\n\n\n\n
dpkg-query: no packages found matching ntp<\/code><\/pre>\n\n\n\n
The ntp<\/em> package is available on the default Ubuntu 18.04 and Ubuntu 20.04 repositories.<\/p>\n\n\n\n
Install ntp<\/em> on Ubuntu 20.04\/18.04 by running the command:<\/p>\n\n\n\n
sudo apt install ntp -y<\/code><\/pre>\n\n\n\n
Verify that that ntp<\/em> package has been installed successfully by checking the version number:<\/p>\n\n\n\n
sntp --version<\/code><\/pre>\n\n\n\n
Output:<\/p>\n\n\n\n
sntp 4.2.8p12@1.3728-o (1)<\/code><\/pre>\n\n\n\n
Running NTPd on Ubuntu 20.04\/18.04<\/h3>\n\n\n\n
After installation NTP is started and enabled to start at boot time:<\/p>\n\n\n\n
systemctl status ntp<\/code><\/pre>\n\n\n\n
\u25cf ntp.service - Network Time Service\n     Loaded: loaded (\/lib\/systemd\/system\/ntp.service; enabled; vendor preset: e>\n     Active: active (running) since Sun 2020-10-11 20:09:21 EAT; 55min ago\n       Docs: man:ntpd(8)\n   Main PID: 567 (ntpd)\n      Tasks: 2 (limit: 585)\n     Memory: 1.5M\n     CGroup: \/system.slice\/ntp.service\n             \u2514\u2500567 \/usr\/sbin\/ntpd -p \/var\/run\/ntpd.pid -g -u 127:133\n\nOnk 11 20:10:28 computers-VirtualBox ntpd[567]: Soliciting pool server 162.159.>\nOnk 11 20:10:29 computers-VirtualBox ntpd[567]: Soliciting pool server 160.119.>\nOnk 11 20:10:29 computers-VirtualBox ntpd[567]: Soliciting pool server 162.159.>\nOnk 11 20:10:29 computers-VirtualBox ntpd[567]: Soliciting pool server 162.159.>\n...<\/code><\/pre>\n\n\n\n
Setting up NTP Server using NTPd on Ubuntu<\/h3>\n\n\n\n
Configure NTP Server on Ubuntu 20.04\/18.04<\/h4>\n\n\n\n
NTP daemon (ntpd)<\/em> main configuration file is \/etc\/ntp.conf<\/code>. The file is configured to enable NTP server to fetch the correct time from NTP servers of higher stratum such as pool.ntp.org<\/em><\/strong>. The pool<\/em><\/strong> directive in the file enables setting of NTP time servers (pool) to use.<\/p>\n\n\n\n
sudo vim \/etc\/ntp.conf<\/code><\/p>\n\n\n\n
# Specify one or more NTP servers.\n\n# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board\n# on 2011-02-08 (LP: #104525). See http:\/\/www.pool.ntp.org\/join.html for\n# more information.\npool 0.ubuntu.pool.ntp.org iburst\npool 1.ubuntu.pool.ntp.org iburst\npool 2.ubuntu.pool.ntp.org iburst\npool 3.ubuntu.pool.ntp.org iburst\n\n# Use Ubuntu's ntp server as a fallback.\npool ntp.ubuntu.com<\/code><\/pre>\n\n\n\n
By default NTP on Ubuntu 20.04\/18.04 uses ubuntu<\/em> pool time servers from the NTP servers pool.ntp.org<\/em><\/strong> as seen from the above output. A list of time servers can be found at NTP Public Pool Time Servers<\/a> where one can choose which timeserver to use according to their timezone. For example to use ke.pool.ntp.org<\/em> pool:<\/p>\n\n\n\n
First comment out the default ubuntu pool timeservers:<\/p>\n\n\n\n
...\n# more information.\n#pool 0.ubuntu.pool.ntp.org iburst\n#pool 1.ubuntu.pool.ntp.org iburst\n#pool 2.ubuntu.pool.ntp.org iburst\n#pool 3.ubuntu.pool.ntp.org iburst\n\n# Use Ubuntu's ntp server as a fallback.\n#pool ntp.ubuntu.com\n...<\/code><\/pre>\n\n\n\n
To add up servers from the ke.pool.ntp.org<\/em> pool add the following entry on the configuration file:<\/p>\n\n\n\n
...\n#Use kenyan pool\npool 0.ke.pool.ntp.org iburst\npool 1.ke.pool.ntp.org iburst\npool 2.ke.pool.ntp.org iburst\npool 3.ke.pool.ntp.org iburst\n...<\/code><\/pre>\n\n\n\n
TIP:<\/em><\/strong> Setting the pool as pool.ntp.org allows the system to determine the nearest time servers to use.<\/em><\/p>\n\n\n\n
iburst<\/em><\/strong> option in the configuration file changes the initial interval of polls to a NTP server in order to speed up the initial synchronization.<\/p>\n\n\n\n
Configure Access Control for NTP Server (Optional)<\/h4>\n\n\n\n
NTP server can optionally be configured to only allow specific NTP client connections to query them using the restrict<\/em><\/strong> directive in the \/etc\/ntp.conf<\/code> configuration file which uses the syntax:<\/p>\n\n\n\n
restrict address [mask mask] [other options]<\/code><\/pre>\n\n\n\n
This access control can be used to limit access to NTP service to particular LAN. For instance to only allow connections from the network 192.168.56.0\/24, define the network address by appending the line:<\/p>\n\n\n\n
restrict 192.168.56.0 mask 255.255.255.0 nomodify notrap<\/code><\/pre>\n\n\n\n
Where:<\/p>\n\n\n\n