Nagios Plugins

Nagios Core can't actually check anything on its own. For every check, it runs a separate program called a plugin and reads the result. Nagios Plugins is the standard collection of these, so almost every Nagios install depends on it.

I am the current maintainer. Most of the code is written by people in the community, so my part is reviewing their pull requests, merging them, and putting out releases.

GitHub | Release notes

2.5 (Mar 31, 2026)

This release had seven changes from seven different contributors.

• check_by_ssh has a new --unknown-timeout flag
• check_http no longer segfaults when an SSL connection fails
• Reverse lookups in check_dns work again
• check_ssh's remote protocol flag works now
• check_icmp gives the right error for the IPv6 address ::
• Some cleanup in check_procs
• The build uses grep -E instead of egrep