Nagios provides central monitoring of the hosts and services in your distributed network. All Opengear console servers (firmware V 2.3.1 or later) have the Nagios NSCA client and the NRPE server software embedded. So they can function as distributed Nagios monitoring servers. These embedded programs enable scheduled check-ins with the central Nagios monitoring server and send check results across the network to the remote monitoring server. In the event that the checks find something wrong with a network service or host resource at a remote site, the console server then informs the central Nagios monitoring server which in turn sends the administrator an alert.
This removes the need for dedicated slave Nagios servers at remote sites. They can also be deployed locally to the Nagios monitoring host server to provide additional diagnostics and points of access to managed devices.
You can freely download the latest Nagios version. Nagios also forms the core of many leading commercial system management solutions such as GroundWork. While Nagios takes some time to configure and install, it provides an outstanding network-monitoring system. With Nagios you can:
- display lists showing in real time the status of each monitored server, network node and service
- use a wide range of freely available plug-ins to make detailed checks of specific services (e.g. don't just check a database server is accepting network connections, check that it can actually validate access requests and return real data)
- display warnings and send warning e-mails or pagers alerts when a service failure or degradation is detected
- assign contact groups who are responsible for specific services in specific time frames
Using your console servers to distribute Nagios monitoring enables you to simply and securely monitor remote sites and nodes distributed behind firewalls. To set this up, you first configure distributed monitoring in the upstream Nagios monitoring host, then configure the console servers for Nagios support:
- Nagios integration is enabled and a path established to the upstream Nagios server
- The embedded NSCA client is then configured to periodically report on Nagios monitored services. NSCA enables scheduled check-ins with the remote Nagios server and is used to send passive check results across the network to the remote server
- The NRPE server is then configured. NPRE is the Nagios daemon for executing plugins on remote hosts, enabling the remote Nagios server to actively request status updates from the console server
- Each of the Serial Ports and each of the Hosts connected to the console server which are to be monitored are then Nagios enabled and any specific Nagios checks configured
- Lastly the upstream Nagios monitoring host must be configured
Once the connection to the upstream Nagios server is configured, and Nagios checks have been configured for Serial Ports and Network Hosts, the distributed check configuration must be imported into your upstream Nagios server.
For convenience, the Opengear console server generates a Nagios configuration snippet, saved on the Opengear unit at:
After copying this file from the Opengear unit, importing it into Nagios is usually as simple as copying it to the conf.d directory under your main Nagios configuration directory, e.g.:
You should then verify the Nagios configuration is okay (nagios -v), then restart Nagios.
... and see Chapter 10 in the Opengear User Manual for more details.
You also can find more distributed Nagios information on: