Following is a list of passive monitoring agents for Nagios and Icinga that I have collected over the internet:
NCPA
NCPA is a relatively new passive monitoring agent.
- Available for Linux (RPM and Deb packages available), Windows and MacOS.
- Has a web based admin page
- Communicates over HTTP protocol.
- Supports both passive and active checks (see here how to execute active checks)
NSCA-ng
An improved version of NSCA. ncsa-ng is a server application, accepting health checks from the agents, and submitting them to Nagios.
See examples in Icinga’s web site.
send_nsca is the agent which is installed on the hosts to be monitored. send_ncsa sends the healthchecks to nsca-ng server.
- Supports encrypted communications between the agent and server using TLS
- Written in C
- Supports submitting both health checks and commands such as service issue acknowledgement to Nagios.
- Can allow only health checks commands to be submitted.
NSCAweb
A passive check agent for sending healtchchecks over HTTP protocol. NSCAweb project is hosted in GitHub and is actively developed and updated.
Note that NSCAweb does not run passive checks automatically – there should be another process or cron job that runs the passive checks and submits their results to NSCAweb.
- Supports buffering of messages to Nagios server in case of a network issue
- Supports SSL encryption of the communications
- Communicates over HTTP protocol
- Sends healthchecks to destinations: another NSCAweb server, Nagios command file (nagios.cmd), NRDP or a file.
- Load balances or failover between multiple URLs of destination
- Can send to multiple destinations
- Written in Python
NSCA
NSCA is the original Nagios passive checks agent. Its code was last updated in 2012.
Configuration example in Icinga’s web site.
- An NSCA instance needs to be installed on the Nagios server. It acts as a server accepting health checks results from the monitored hosts, and submits them to the Nagios external command file.
- On the monitored hosts, NSCA is installed and configured as agent, sending the health checks to the NSCA instance which is installed in the Nagios server.