This is a [meta-]port of the Nagios plugins found at silfreed.net.

These are useful for those individuals wishing to monitor network device
health via SNMP, using Nagios, and to generate alerts accordingly. When
used with Nagiostat, RRDTool-based graphs can be generated from within
the Nagios monitoring framework, much like Cricket.

It includes the following checks: check_max_clients_route,
check_pm3_clients_route, check_snmp_counter, check_snmp_gauge,
check_snmp_if, check_snmp_if_max, check_tcping, and dns_delegation.

WWW: http://www.silfreed.net/download/progs/nagios/