How you can setup NTP on your Linux System.

What the Heck is this NTP?

NTP is a timekeeper which receives time from an NTP server, which in turn, receives precise time from sources like an atomic clock or GPS and synchronizes your computer's local time with it.

Why is NTP so Important?

Because,

"Good Security Starts With Good Timing."

While it's not a required thing, it's recommended to have your system clock Synchronised with the NTP server for accurate timestamping.

On Servers where if any Error occurs you need to trace back when that issue happened and having your Clock synchronised helps a lot for tracing and relating all the service issues.

Also if you have services like Cron Jobs active having accurate system timing is a must so the system tasks will execute exactly when needed.

Installing NTP on Your Linux Server.

While I tried this on Ubuntu 20.04 This can work on any Unix-based Operating System

1. Introducing Chrony

While there are other packages which do the job like timedatectl or timesyncd chrony is a much better option compared to others.

Installing chrony will create a daemon named chronyd and a command-line tool named chronyc for managing its service.

2. Installing Chrony and Enabling The Chrony Service

On Debian/ Ubuntu Systems you can directly install using apt

sudo apt install chronyd

For Red hat/Fedora use yum

sudo yum install chronyd

Start the installation of chronyd using systemctl

sudo systemctl start chronyd

3. Configuring NTP server

Configuration file for your Chronyd is at /etc/chrony/chrony.conf You can view the contents of the file using the following command

cat /etc/chrony/chrony.conf

You will see some NTP servers pre-configured in configuration file

pool ntp.ubuntu.com        iburst maxsources 4
pool 0.ubuntu.pool.ntp.org iburst maxsources 1
pool 1.ubuntu.pool.ntp.org iburst maxsources 1
pool 2.ubuntu.pool.ntp.org iburst maxsources 2

If you want you can change this NTP servers with the one you want to use.

I recommend finding servers nearest to your server location for lower latency

3. Verify and Apply new configurations

You can check if NTP servers are working or not by running the following command

chronyc activity

It will list the information about synchronisation like the example below.

200 OK
8 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address

Here we can see that 8 sources are online which means our synchronisation is working.

4. Celebrate 🥳

Congratulations! You have successfully configured NTP on your Linux Server.