Nagios snmp checks using PHP


I have a little problem with this plugin:;d=1

It works, but once when I try to check interface Vlan2 receive error:

Warning: snmpget(): Error in packet: (noSuchName) There is no such variable name in this MIB. in /usr/local/nagios/libexec/cisco on line 229

Warning: snmpget(): This name does not exist: IF-MIB::ifOutOctets.34 in /usr/local/nagios/libexec/cisco on line 229
Couldn't get interface output - UNKOWN

The command I run:

Cisco model is 3725, command works for another interfaces - Vlan1 is ok.

Any suggestion? Or another script which I can use to this model cisco?