When I use check_snmp!-C tesco-cn@cisco-l3 -o sysUpTime.0 I can get the running time,but when I run check_snmp!-C tesco-cn@cisco-l3 -o ifOperStatus.1 -r 1 -m RFC1213-MIB this command met “SNMP CRITICAL - down(2)” on the same switch. What is the problem and how to solve it?? Somebody met it yet??