check_pf

Download | Installation

check_pf is a plugin intended for use with the Nagios network monitoring system. This plugin checks the status of PF,
the (excellent) OpenBSD packet filter, and compares the current state count to given or default thresholds, returning the result. It is written in C.

The thresholds may be specified on the command-line, but if they are not, check_pf will base the thresholds off of the current hard state limit set in pf(4).

PF OK - states: 4342 (14.5% - limit: 30000)

# check_pf -h
check_pf 0.1

This plugin checks if PF is enabled, and if it is, the number of states
currently in the state table.

The current state count is compared to the given (or default) thresholds and
the proper Nagios state value is returned.

Usage: check_pf [-Vh] [-w number] [-c number]
        -V        - Print the plugin version
        -h        - Print the plugin help
        -w number - Warning when <number> states (default: 80% of state limit)
        -c number - Critical when <number> states (default: 90% of state limit)

Download

check_pf-0.1.tar.gz (signature) - 3/8/07

Installation

If you are using FreeBSD, there is a port for check_pf (net-mgmt/nagios-pf-plugin).

Or, to install this plugin manually, do the following:

# tar xzf check_pf-XX.tar.gz
# cd check_pf-XX
# make && make install

You can manually specify the location to install the plugin:

# make install DESTDIR=/path/to/plugins/

You can remove it as follows:

# make uninstall DESTDIR=/path/to/plugins/

check_pf needs read-access to pf(4). You will probably be running check_pf through Nagios/NRPE, so the following should work:

# chmod 640 /dev/pf
# chgrp nagios /dev/pf

To make sure the changes persist across reboots (FreeBSD 5.x and later), add the following to /etc/devfs.conf:

# nrpe2/nagios needs to be able to read statistics
own     pf    root:nagios
perm    pf    0640

There are other ways to do accomplish the same thing, but DON'T just make the device available to everyone.