How to verify NTP is working Or not (Check Status of NTP)

To verify that the Network Time Protocol (NTP) is working on a Linux or Unix system, you can use the following steps:

1. First, check if the NTP daemon (ntpd) is running by using the ps command. For example, you can use the following command to check if ntpd is running:

ps aux | grep ntpd

If ntpd is running, you should see output similar to this:

root      1234  0.0  0.1  12345  6789 ?        Ss   14:23   0:00 ntpd -p /var/run/ntpd.pid -g -u 123:456

If ntpd is not running, you will not see any output.

2. If ntpd is running, check if the system clock is synchronized with an NTP server by using the ntpq command. For example, you can use the following command to check the status of the NTP server:

ntpq -p

If the system clock is synchronized with an NTP server, you should see output similar to this:

remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*192.168.1.1    123.456.789.0      2 u  497  256  377   35.936    1.935   0.001

The * in the first column indicates that the system clock is synchronized with the server listed in the second column. The st column shows the status of the server, with a value of "2" indicating that the server is a normal NTP server.

If the system clock is not synchronized with an NTP server, you will not see any output, or you may see an error message indicating that the system clock is not synchronized.

3. If the system clock is not synchronized with an NTP server, you may need to check the NTP configuration file (usually /etc/ntp.conf) to make sure that the correct NTP servers are listed. You can also use the ntpdate command to manually synchronize the system clock with an NTP server. For example, you can use the following command to synchronize the system clock with the 192.168.1.1 NTP server:

ntpdate 192.168.1.1

This will synchronize the system clock with the 192.168.1.1 NTP server.

If you are still having trouble getting NTP to work, you may need to troubleshoot the issue further. For example, you may need to check the system logs for error messages, or check the firewall rules to make sure that NTP traffic is allowed.

For more information about NTP and how to troubleshoot NTP issues, you can consult the NTP documentation or use the man ntp command to see the manual page.