You monitor three Cisco routers with NPM.

NPM uses SNMP to collect utilization statistics from network devices, such as routers, switches, firewalls, etc. If NPM only shows Availability and Response Time statuses for a device, it means that SNMP is not configured correctly on that device or NPM cannot access the device via SNMP1. Some possible reasons for this are:

The device does not support SNMP or SNMP is disabled on the device

The device has a different SNMP version or community string than NPM

The device has a firewall or access control list that blocks SNMP traffic from NPM

The device has a misconfigured SNMP agent or MIB To troubleshoot this issue, you can use the SNMP Test Tool in NPM to verify the SNMP settings and connectivity of the device2. You can also check the device logs and configuration to ensure that SNMP is enabled and properly configured3. References: 1: Network Performance Monitor Administrator Guide - Troubleshoot SNMP issues 2: Network Performance Monitor Administrator Guide - Test SNMP access 3: Network Performance Monitor Getting Started Guide - Troubleshoot SNMP issues