check_snmp_if

check_snmp_if is a Nagios plugin that checks interfaces via SNMP (IF-MIB). Unlike many other scripts, it is designed to check all interfaces on network devices that support IF-MIB from RFC 2863 (such as switches, routers, firewalls). Exclusions can be made based on a variety of fields, including interface name, alias and type.

check_snmp_if checks interface status, promiscuous mode, input and output bandwidth utilization, and broadcast and error packet levels among other things.

In order to reduce execution time, SNMP requests can be performed in parallel, so that distant devices with hundreds of interfaces can be checked in just a few seconds.

SNMP version 1 is not supported because requests are aborted if a non-supported object is encountered. There are other reasons you should not be using SNMP version 1 - one being that it does not support 64-bit values. In the author's experience however, most devices that support SNMP version 1 also support version 2 - usually without modifications.

check_snmp_if is written in Perl.