Time Synchronization with NTP | System Administration

Network Time Protocol – System Administration

NTP Time Synchronization | System Administration

We are going to show you a simple and handy way to setup NTP over single/multiple servers connected to a network for time synchronization.

What is NTP?

Network Time Protocol (NTP) is a networking protocol for Clock synchronization between computer systems over packet-switched data networks. Basically, a client requests the current time from a server and uses it to set its own clock. Learn More

Pre Requests

• Our example includes Ubuntu (Linux) server running APACHE and PHP.
• SSH access to your Linux server with “sudo privileges”.

NTP Poll Client Installation

$ apt-get install ntp

Configuration

Edit /etc/ntp.conf to add/remove server lines. By default these servers are configured:

# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
server 0.ubuntu.pool.ntp.org
server 1.ubuntu.pool.ntp.org
server 2.ubuntu.pool.ntp.org
server 3.ubuntu.pool.ntp.org

Our Server is located in N.Virginia region which is in North America, therefore I am using NTP Pool Servers which are falling in North America Region. You can adjust them according to the location of Your server. Just need to comment out default servers listed in ntp.conf file above. Use link to find your server Location: NTP Server Location

server 0.north-america.pool.ntp.org
server 1.north-america.pool.ntp.org 
server 2.north-america.pool.ntp.org 
server 3.north-america.pool.ntp.org

NTP Service Restart

$ sudo /etc/init.d/ntp restart

or

$ sudo systemctl reload ntp.service

View Status

$ sudo ntpq -p

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+stratum2-2.NTP. 129.70.130.70    2 u    5   64  377   68.461  -44.274 110.334
+ntp2.m-online.n 212.18.1.106     2 u    5   64  377   54.629  -27.318  78.882
*145.253.66.170  .DCFa.           1 u   10   64  377   83.607  -30.159  68.343
+stratum2-3.NTP. 129.70.130.70    2 u    5   64  357   68.795  -68.168 104.612
+europium.canoni 193.79.237.14    2 u   63   64  337   81.534  -67.968  92.792

Do share the tutorial if you find it useful. Cheers!