SCP-NPM - SolarWinds Network Performance Monitor (NPM) Exam

When a router monitored by NPM reboots, the interface indexes may change, causing the interface statuses to become unknown in NPM. This is because NPM uses the interface indexes to identify and poll the interfaces. To resolve this issue, you need to remove the unknown interfaces from NPM and then run a list of resources on that node to discover the interfaces with the new index IDs. You can then add the interfaces back to NPM and resume monitoring them. References:

• Allow Change the Interface Index - Forum - Network Performance Monitor (NPM) - THWACK Products
• Edit interface properties in NPM - SolarWinds
• SCP Study Aid - SolarWinds (page 6)

PerfStack is a feature of the Orion Platform that allows you to compare and correlate performance data from multiple SolarWinds products and entities in a single view1. You can drag and drop metrics from different sources, such as NPM, SAM, NCM, NTA, and more, and create custom dashboards that help you troubleshoot complex network issues2. PerfStack can also show historical data and baselines for comparison3. References: 1: Network Performance Monitor Administrator Guide - Use PerfStack to troubleshoot issues 2: Network Performance Monitor Getting Started Guide - Troubleshoot your network with PerfStack 3: SolarWinds Certified Professional Program - Diagnostics and Troubleshooting Exam Study Guide - Use PerfStack to troubleshoot issues

An OID (Object Identifier) is a unique identifier for a specific variable in a MIB (Management Information Base) that can be polled or monitored by SNMP (Simple Network Management Protocol). However, not all OIDs are supported by all devices or SNMP agents, which are software components that collect and report the MIB data. If you select an OID that is not supported by the device or the SNMP agent, you will get an “OID not supported” error when you try to create a custom poller for that device in NPM (Network Performance Monitor). This means that the device or the SNMP agent does not have the information for that OID or does not respond to the SNMP request for that OID12.

To resolve this issue, you can try the following steps34:

• Verify that the device supports the OID that you want to monitor. You can use the MIB Browser or the MIB Walk tool to browse the MIB tree of the device and find the OID. You can also check the device vendor’s documentation or website for the supported OIDs and MIBs.
• Verify that the SNMP agent on the device is configured properly and has the latest version. You may need to update the SNMP agent or enable some features or extensions to support the OID. You can also check the SNMP agent’s logs or status for any errors or warnings.
• Verify that the SNMP credentials and settings are correct and match the device’s configuration. You may need to use a different SNMP version, community string, port, or timeout value to communicate with the device. You can also test the SNMP connectivityusing the SNMP Test tool or the Test button in the UnDP (Universal Device Poller) application.
• Verify that there are no network issues or firewalls that are blocking the SNMP traffic between the NPM server and the device. You may need to allow the SNMP protocol and port on the firewall or router, or use a different network path or interface to reach the device. You can also use the Ping or Traceroute tools to check the network connectivity and latency.

References: 1: What is an OID?5, 2: The OID is not supported, 3: Troubleshoot Unknown Nodes, 4: Troubleshoot SNMP issues