Version 3.0.0 (Johann Georg Elser) released

Lorenz Kästle, June 16, 2026

The Monitoring Plugins Development Team finally announces version 3.0.0 of the Monitoring Plugins.

This is a rather big release as the C part of the project received a huge amount of changes, some of them only internally, but also to the user facing side of things. Most notably is the change in the output of many plugins, which is now mostly multi line by default and hopefully improves the readability. Altough we were careful to avoid breaking anything, it can not completely ruled out, that in some scenarios there are new bugs. Please report (and fix) them :-)

This is also the first release with a code name (because those are cool, right?), which is Johann Georg Elser for this release. You can find more on this Person on Wikipedia.

We have to thank a lot of people for reporting problems or contributing fixes and enhancements. Especially the OpenBSD crew was very helpful with testing the release candidates and reporting problems promptly (mostly with patches attached). It is a joy to have such wonderful people on the project.

Some special thanks go to NLnet and the french goverment for granting us the Blue Hat Prize which made a lot of the work possible.

Last, but not least, we, of course, thank everyone who reported a problem, posted a patch or tested the release candidates to find most of the new bugs. We do appreciate it.

You can get the tarball from our download page.

General changes

Specific changes

check_curl

check_curl received a lot of changes which improve the documentation and fix several bugs. It is also not considered experimental anymore.

Additionaly check_curl can now be configured to handle cookies internally without saving cookies to the filesystem.

A new --proxy flag allows setting the proxy similar to the curl tool itself.

check_http

check_http is now considered deprecated and will not receive attention any more. It is replaced by check_curl

check_snmp

check_snmp does not execute snmpget or snmpgetnext anymore but executes the net-snmp calls natively now.

check_nwstat

check_nwstat was removed, due to its perceived insignificance in the current IT world. This reduces the maintenance load and ressource consumption in general.

check_ntp

check_ntp was removed. It was faulty by design and marked as deprecated for a long time. The replacements are check_ntp_time and check_ntp_peer.

check_ntp_time

check_ntp_time now does include a delay between consecutive queries to avoid triggering rate limiting on NTP servers.

check_nt

check_ntwas removed. It is no longer useful in current setups and hasn't been for some time.

check_by_ssh

check_by_ssh ignores output on stderr by default now. This should avoid false positives for warnings by the OpenSSH client (especially about the server missing Post-Quantum cryptography.

check_dns

check_dns now ignores CNAMES in reverse DNS mode.

check_fping

If during compilation fping 5.2, 5.3 or higher are present, check_fping will be able to use new options which were introduced with these versions. These options are (equivalent to the ones with the same name in fping) --fwmark, --icmp-timestamp and --check-source. The older flags --dontfrag and --random were also added.

Also the -4 and -6 flags may not have worked as intented and should be fixed now.

check_mysql

check_mysql should now be able to correctly detect whether a replica is attached and working correctly. Changes were necessary here to adapt to changes in the naming convention in MySQL.