Network Management

Incorrect Auto-Dependencies / Topology Due to misleading CAM/Bridge data

In some environments, automatic dependencies and topology relationships in SolarWinds Network Performance Monitor (NPM) may be calculated incorrectly. This typically presents as unexpected or wrong parent-child dependencies between nodes. The issue can occur when CAM/Bridge table data from monitored devices is misleading or interpreted in a way that produces invalid topology. This article explains the cause and provides a configuration-based workaround using Advanced Configuration → CalculationConfiguration settings to improve the accuracy of auto-dependencies.

First published date

4/2/2026 4:46 AM

Last published date

4/2/2026 4:48 AM

Overview

This article explains how automatic dependencies and topology mapping may be calculated incorrectly due to CAM and Bridge data.

  • Visual inspection of Maps and Dependencies
  • Unexpected alert suppression behavior
  • Comparing discovered relationships with the known physical/logical network design

Symptoms

You may observe one or more of the following:

  • Nodes show incorrect parent-child relationships in the dependencies view.

  • Maps or topology views display unexpected links between devices.
  • Alert suppression does not behave as expected because auto-dependencies are wrong or misleading (for example, downstream devices are not properly suppressed when their true upstream device is down).

This behavior is most likely when:

  • Devices expose CAM/Bridge tables that are incomplete, stale, or misleading, and the Topology Calculator includes those tables in its logic, resulting in invalid topology or wrong auto-dependencies.

Product section

Network Performance Monitor

Cause

This issue occurs when the topology Calculator uses a combination of data sources (including CAM/Bridge tables) to infer Layer 2 relationships and build topology and automatic dependencies.

When this occurs, auto-dependencies may:

  • Show the wrong parent for one or more nodes.
  • Create spurious links between nodes that are not actually upstream/downstream of each other.
  • Interfere with proper alert suppression and root cause identification.

To mitigate this, you can configure NPM to exclude CAM/Bridge data from the topology calculation and optionally reduce duplicate/ambiguous relationships.

Resolution

To resolve this issue, use the Advanced Configuration page to update CalculationConfiguration settings:

  1. Open the Advanced Configuration page

    On the main Orion server, open a browser and navigate to:

    http://<orion_server>/Orion/admin/advancedconfiguration/global.aspx

    Replace <orion_server> with the hostname or IP of your Orion server.

  2. On the Advanced Configuration page, find the CalculationConfiguration setting.

    • Click to open it for editing.

     

  3. Find BridgeNodeDataLoader and set to false

    This prevents CAM/Bridge table data from being used in the topology calculation, reducing the likelihood that misleading CAM/Bridge entries will generate incorrect auto-dependencies.

  4. Optionally, find SkipSysNameIpDuplicates and set to true 
  5. Save changes

Wait up to a few hours for topology and auto-dependencies to be recalculated.  If the problem remains, please contact SolarWinds Support for further review

For a conceptual overview of how parent-child dependencies work (independent of this specific issue), refer to the public Parent-Child dependencies article in the SolarWinds Success Center.