Security Controls

TIME-3120 - Reliability of NTP servers


Lynis tests if the used NTP server candidates are reliable enough to be used. If items show up with a dash or minus, they are unreliable and should be checked or replaced. The NTP configuration and time synchronization in particular, is important for systems. It helps with properly logging the actual time, which is needed for many services. Having the right time is also important for accounting purposes and forensics.



How to solve

Determine the list of peers with ntpq -p and check for the servers with a dash or minus sign. If these servers keep showing up, check their availability or any firewall rules which might obstruct synchronization from occurring between those systems and the target system.

Linux and Unix System Hardening

This information is provided as part of the Lynis community project. It is related to Lynis control TIME-3120. All information should be considered as-is, without guarantees. Any advice or snippets should be tested before implementing in production environments.


Lynis is a technical security audit tool for systems running Linux, UNIX, *BSD, and macOS. It is open source software and free to use. The project has an active community, and can also be found on GitHub.

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