SNMP V3 config Help required



I have installed Opsview 3.9 which installs Nagios Core 3.2.2 I have configured Cisco 1800 Router to be monitored using SNMP V3 post the config Test SNMP Connection cones back with messgage as given below, when I check on the host none of the parameters are getting monitored

CPU Load, memory utilization, Interface Speed and Status SNMP Agent Uptime gives warning with message Agent not responding Tried SNMP v1 and v2 but does not try polling in v3

has some one configured snmnp v3 please require help

Sucessfully connected via SNMP!
System Description: CISCO ISO Software, 1841 Software (C1841-IPBASE-M), Version 12.4(15)T10,RELEASE SOFTWARE(fc3)