Now that we are able to query information from Windows and UNIX boxes, it would be good to know how to integrate SNMP checks with Nagios. The Nagios plugins package comes with a plugin called check_snmp for checking SNMP parameters and validating their value. The plugin uses the snmpget and snmpgetnext commands from Net-SNMP, and it does not work without these commands. The syntax of the check_snmp command is as follows:

check_snmp -H <ip_address> -o <OID> [-w warn_range] [-c crit_range]
           [-C community] [-s string] [-r regex] [-R regexi]
           [-l label] [-u units] [-d delimiter]  [-D output- delimiter]
           [-t timeout] [-e retries] [-p port-number] 
           [-m miblist] [-P snmp version] [-L seclevel] [-U secname]
           [-a authproto] [-A authpasswd] [-X privpasswd]

The following table describes the commonly-used options accepted by the plugin. Options that are required are marked in bold.