What are common troubleshooting steps when a node is not polled or shows Unknown in NPM?

What are common troubleshooting steps when a node is not polled or shows Unknown in NPM?

• A. Check device reachability, DNS resolution, SNMP/WMI credentials, firewall rules, polling interval, and Orion services; verify that the node is included in the discovery results.
• B. Reboot the Orion server only.
• C. Remove the node from discovery and re-add it; no other checks.
• D. Increase polling interval to resolve Unknown state.

Answer: (A)

When a node isn’t polled or shows Unknown in NPM, the main idea is to verify end-to-end connectivity and polling configuration between the Orion Platform and the node. Start by confirming device reachability from the Orion server, then ensure DNS resolves properly so the node can be located reliably. Check that the SNMP or WMI credentials used for polling are correct and have the necessary permissions. Review firewall rules to make sure the required ports for SNMP or WMI are open between the Orion server and the node. Look at the polling interval to ensure it’s appropriate and not set in a way that prevents timely polling. Finally, verify that the node is included in discovery results so it is part of the monitored set. This broad checklist targets the typical blockers: if the device isn’t reachable, if name resolution fails, if authentication is incorrect, if ports are blocked, or if the node isn’t properly discovered, polling will fail or show Unknown. Rebooting the Orion server alone doesn’t fix these root causes; removing and re-adding the node without diagnosing the underlying issue can miss problems, and simply increasing the polling interval can hide the problem rather than resolve it.

When a node isn’t polled or shows Unknown in NPM, the main idea is to verify end-to-end connectivity and polling configuration between the Orion Platform and the node. Start by confirming device reachability from the Orion server, then ensure DNS resolves properly so the node can be located reliably. Check that the SNMP or WMI credentials used for polling are correct and have the necessary permissions. Review firewall rules to make sure the required ports for SNMP or WMI are open between the Orion server and the node. Look at the polling interval to ensure it’s appropriate and not set in a way that prevents timely polling. Finally, verify that the node is included in discovery results so it is part of the monitored set. This broad checklist targets the typical blockers: if the device isn’t reachable, if name resolution fails, if authentication is incorrect, if ports are blocked, or if the node isn’t properly discovered, polling will fail or show Unknown. Rebooting the Orion server alone doesn’t fix these root causes; removing and re-adding the node without diagnosing the underlying issue can miss problems, and simply increasing the polling interval can hide the problem rather than resolve it.