ntpq Command: Tutorial & Examples
Monitor the NTP server
ntpq stands for Network Time Protocol Query. It's a client program that enables you to query NTP servers
about their current state and to request changes in that state.
How ntpq Works
The ntpq command communicates with the NTP server, which uses the Network Time Protocol (NTP) to
synchronize all participating computers to within a few milliseconds
of Coordinated Universal Time (UTC). ntpq uses the NTP mode 6 control message format to query the
NTP server about its current state and to request changes in that state.
Importance of ntpq
The ntpq command is crucial in system administration, especially when it comes to troubleshooting. If your system's
time is not correct, it can cause problems like failed user authentications, issues with data synchronization, and even
complete network failure. With ntpq, you can monitor your NTP server and ensure that your system time is accurate,
avoiding these potential problems.
How to Use ntpq
To use the ntpq command, you simply type ntpq followed by the parameters and arguments that you need. For instance,
to query an NTP server, you would use the -p parameter like so:
ntpq -p
This command would display a list of peers known to the NTP server as well as a summary of their state.
Common ntpq Parameters
There are several parameters you can use with the ntpq command, but here are some of the most common:
-p: This parameter lists the peers known to the NTP server along with a summary of their state.-c: This parameter allows you to run a specific command and then exit.
Potential Problems and Pitfalls
While ntpq is a useful tool, it's not without its potential problems and pitfalls. One common issue is that if a
firewall is blocking NTP traffic, ntpq will not be able to communicate with the NTP server. This can also occur if the
NTP service is not running on the server.
Additionally, ntpq does not give you the system's time, but rather the time of the NTP server. If your system's time
is not being updated correctly, you will need to troubleshoot the issue, which could be a problem with the system's time
configuration or an issue with the NTP service itself.
Example Usage of ntpq
Here are some examples of how to use the ntpq command:
To display a list of peers known to the NTP server along with a summary of their state:
ntpq -p
To run the rv command and then exit:
ntpq -c rv
The output of ntpq -p might look like this:
remote refid st t when poll reach delay offset jitter
==============================================================================
*ntp.your.org .GPS. 1 u 63 128 377 0.476 -0.170 0.010
This output indicates that your NTP server is working fine and that it’s synchronized with the remote NTP
server ntp.your.org.
In conclusion, ntpq is a valuable tool for any Linux server administrator. It allows for quick and easy monitoring of
NTP servers, ensuring your system time remains accurate. As with any command, be sure to read
the man pages (man ntpq) for more information and other available options.
