info nagios core

Good Evening,
I need help about check_snmp! command for internal temperature monitoring
of a switch/router.
I must write a service in my configuration file like this:

define service{
        use                     generic-service ;
        host_name               RouterBoard
        service_description     Port 1 Link Status
        check_command           check_snmp!-C public -o ifOperStatus.2 -r 1
-m RFC1213-MIB
        }
What is the correct syntax?