Objective is to monitor a switch via snmp. With the default installation of Nagios3 via aptitude, there are some missing files. Here are some of the steps I have taken but still incomplete.

1) edit /etc/nagios3/nagios.cfg to enable cfg_file=/etc/nagios/objects/switch.cfg
2) create the directory /etc/nagios3/objects since it is non-existent with the default installation.
3) copy the sample configuration file from /usr/share/doc/nagios3-common/examples/template-object/switch.cfg to /etc/nagios3/objects
4) edit /etc/nagios3/objects/switch.cfg with the required snmp string.
5) restart nagios3

Error: Service check command 'check_snmp' specified in service 'Uptime' for host 'switch1' not defined anywhere

However, when I did a locate for 'check_snmp', I have it in /usr/lib/nagios/plugins/check_snmp

Any advice is greatly appreciated.

Thanks!

Before you can use a check by name for any service or host configuration it must be known in the Nagios configuration. Add it to your "commands.cfg", the file contains enough command definition examples to show you how.