NSClient++ (nscp) aims to be a simple yet powerful and secure monitoring daemon. It was built for Nagios/Icinga, but nothing in the daemon is Nagios/Icinga specific and it can be used in many other scenarios where you want to receive/distribute check metrics.
The daemon has 3 main functions:
- Allow a remote machine (monitoring server) to request commands to be run on this machine (the monitored machine) which return the status of the machine.
- Submit the same results to a remote (monitoring server).
- Take action and perform tasks.
NSClient++ can be found at: http://nsclient.org
Documentation can be found at: http://docs.nsclient.org
NSClient++ is designed to be open ended and allow you to customize it in any way you design thus extensibility is a core feature.
- ExternalScripts responds to queries and are executed by the operating system and the results are returned as-is. This is generally the simplest way to extend NSClient++ as you can utilize whatever infrastructure or skill set you already have.
- LuaScripts are internal scripts which runs inside NSClient++ and performs various tasks and/or responds to queries. This is the best option if you want to allow the script to run on any platform with as little infrastructure as possible.
- PythonScripts are internal scripts which runs inside NSClient++ and performs various tasks and/or responds to queries. Python is an easy and powerful language but it requires you to also install python which is often not possible on server hardware.
- .Net modules similar to Native modules below but written on the dot-net platform. This allows you to write components on top of the large dot-net ecosystem.
- Modules are native plugins which can extend NSClient++ in pretty much any way possible. This is probably the most complicated way but gives you the most power and control.
Since NSClient++ is meaningless by itself it also supports a lot of protocols to allow it to be used by a lot of monitoring solutions.
- NRPE (Nagios Remote plugin Executor) is a Nagios centric protocol to collect remote metrics.
- NSCA (Nagios Service Check Acceptor) is a Nagios centric protocol for submitting results.
- NSCP is the native NSClient++ protocol (still under development)
- dNSCP is a high performance distributed version of NSCP for high volume traffic.
- NRDP is a replacement for NSCA.
- check_mk is a protocol utilized by the check_mk monitoring system.
- Syslog is a protocol primarily designed for submitting log records.
- Graphite allows you do real-time graphing.
- SMTP is more of a toy currently.
NSClient++ should run on the following operating systems:
- Windows: In theory from Windows XP with lots of service back (verified Windows 2008 R2 and later)
- Linux: Debian, Centos and Ubuntu (and possibly others as well)
The following packages are produced by the official build pipelines. Pick the one that matches your operating system and architecture:
| Operating system | Version | Architecture | Package / artifact name | Notes |
|---|---|---|---|---|
| Windows (modern) | Windows 10 / 11, Server 2016 / 2019 / 2022 / 2025 | x64 (64-bit) | NSCP-<version>-x64.msi |
Recommended for all modern Windows systems. Built with MSVC 2022. |
| Windows (modern) | Windows 10 / 11, Server 2016 / 2019 / 2022 / 2025 | x86 (32-bit) | NSCP-<version>-Win32.msi |
Use only on 32-bit Windows installations. Built with MSVC 2022. |
| Windows (modern) | Windows 11 ARM, Server 2025 ARM | ARM64 | NSCP-<version>-ARM64.msi |
Native ARM64 build, cross-compiled with the v143 toolset. Use this on Windows-on-ARM devices (e.g. Surface Pro X / Copilot+ PCs, ARM-based Azure VMs). |
| Windows (legacy) | Windows XP and above | x86 (32-bit) | NSCP-<version>-Win32-legacy-xp.msi |
Statically linked, built with the v141_xp toolset. Use this on any Windows older than Windows 10 / Server 2016. Works on x64 versions of these older OSes too. |
| Ubuntu | 24.04 LTS (Noble) | x64 (amd64) | NSCP-<version>-ubuntu-24.04-amd64.deb |
Should also install on recent Debian/Ubuntu derivatives with compatible glibc and Lua 5.4. |
| Ubuntu | 24.04 LTS (Noble) | ARM64 (aarch64) | NSCP-<version>-ubuntu-24.04-arm64.deb |
For 64-bit ARM hosts (e.g. AWS Graviton, Ampere Altra, Raspberry Pi 4/5 running Ubuntu 24.04 arm64). |
| Rocky Linux / RHEL / AlmaLinux | 9 | x64 (x86_64) | NSCP-<version>-rocky-9-x86_64.rpm |
Compatible with RHEL 9 and other RHEL 9 rebuilds (AlmaLinux 9, Oracle Linux 9, CentOS Stream 9). |
| Rocky Linux / RHEL / AlmaLinux | 9 | ARM64 (aarch64) | NSCP-<version>-rocky-9-aarch64.rpm |
64-bit ARM build for RHEL 9-family distributions. |
| Rocky Linux / RHEL / AlmaLinux | 10 | x64 (x86_64) | NSCP-<version>-rocky-10-x86_64.rpm |
Compatible with RHEL 10 and other RHEL 10 rebuilds. |
| Rocky Linux / RHEL / AlmaLinux | 10 | ARM64 (aarch64) | NSCP-<version>-rocky-10-aarch64.rpm |
64-bit ARM build for RHEL 10-family distributions. |
In addition, a stand-alone check_nsclient binary is published alongside each Linux package for use as a Nagios/Icinga check plugin.
Note: On unsupported distributions you can build from source — see build.md.
NSClient++ is built using CMake and Visual Studio 2022. You can find detailed instructions for building locally in the build.md file.
