Network Management

NPM Network Topology widget displays interfaces as Unknown

This article describes how to handle interfaces that appear as "Unknown" in the NPM Network Topology widget.

First published date

10/24/2018 5:14 PM

Last published date

7/17/2026 3:34 PM

Overview

This article discusses how to address the issue where interfaces are displayed as Unknown in the Node Details page while accessing the NPM Network Topology resource. 

Product section

Network Performance Monitor

Cause

  1. Devices that only respond to ICMP and cannot be determined to be directly connected to a known device can only be shown as Unknown devices. During Discovery, you can filter out ICMP interfaces, if necessary. 
  2. Topology is Layer3Subnet type and this doesn't poll interfaces by design and will be shown as unknown

  3. When some data sources provide only partial information, additional Node‑to‑Node or Node‑to‑Interface connections may be created alongside the primary Interface‑to‑Interface connection. This can result in entries where one or both interfaces cannot be fully identified, which then show as Unknown or appear to be redundant in the NPM Network Topology widget.

Resolution

1. To check that interfaces are being monitored:

  1. Open the Node Details page of the affected node.
  2. Click List Resources.
  3. Verify that the affected interfaces in NPM Network Topology widget are selected.

When configuring object discovery with the Network Sonar Wizard, you can filter out interfaces that only respond to ICMP pings. See Discover your network for the SolarWinds Platform.
 



2. Access your SolarWinds Platform Server

  1. Open Database Manager as mentioned here
  2. Find TopologyConnections table.
  3. Find the desired connection and check on LinkType, if its Layer3Subnet, interfaces / connections will be unknown
  4. Please contact Support if you have further queries.

3.  Filter out topology connections with unidentified interfaces

If the NPM Network Topology widget still shows multiple connections with interfaces listed as Unknown, even though discovery and monitoring are configured correctly, you can filter out connections where the source or destination interface cannot be identified.

  1. In the SolarWinds Platform web console, go to a view that contains the NPM Network Topology widget (for example, a Node Details page for an affected node).

  2. In the upper‑right corner of the NPM Network Topology widget, click Edit.

  3. Locate the following fields:

    • Source Interface Filter (SQL)

    • Destination Interface Filter (SQL)

  4. To hide connections that involve unidentified interfaces, enter the following condition in both filter fields:

InterfaceID IS NOT NULL

  1. Click Submit to save the changes.

  2. Verify that the NPM Network Topology widget now shows only connections where both endpoints are associated with a valid interface.