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Home > Success Center > Network Performance Monitor (NPM) > Remove disappeared APs

Remove disappeared APs

Updated March 8th, 2018



By default, Wireless Access Points that disappear are removed from the database. This means that they cannot be alerted on by Orion Alerts.

We can modify the configuration of Orion to change this behavior so that Access Points which disappear will be left in the Orion in an Unknown State.


If you implement the following configuration change, access points will no longer be deleted from the database.


Follow the instructions for your NPM version.

If the APs are not removed after following these steps, it could be due to the device recording the details of the AP rather than dropping the data.

NPM 11.5.3 and earlier

SolarWinds strongly recommends that you create a backup of the following file:

C:\Program Files (x86)\SolarWinds\Orion\Wireless\SolarWinds.Wireless.Collector.dll.config

Modify the CONFIG file using a text editor:

  1. Find the following key:
    <add key="RemoveDisappearedAPs" value="True" />
  2. Change the key to the following:
    <add key="RemoveDisappearedAPs" value="False" />
  3. Save the changes.
  4. Restart Orion Services.


The functionality works in the following way:

<add key="RemoveDisappearedAPs" value="True" />

  •  When the AP disappears from the controller's SNMP, it's removed from NPM.
  •  An AP which disappears cannot be alerted on as it gets removed from the Database.


<add key="RemoveDisappearedAPs" value="False" />

  • When an AP disappears from the WLC's SNMP, the Access Point goes into an Unknown State in NPM.
  • If the AP appears on another WLC, it will appear as a new Access Point.
  • When the AP comes back to the old WLC again, the once disappeared AP is marked as UP again.
  •  An alert can be triggered for when a AP goes into an Unknown State (Disappeared) and reset the alert when the AP reports in an Up status.


NPM 12.0 and later

  1. Go to the Orion Web Console.
  2. Change the URL to:
    http:YOUR IP OR HOSTNAME/Orion/Admin/AdvancedConfiguration/Global.aspx

    Do not make any configuration changes to any entries in the Setting pages unless advised to by SolarWinds Support or another document in the SolarWinds Success Center. Changing settings could have negative consequences in your environment.

  3. Find the Wireless Section.

  4. De-select the setting for RemoveDisappearedAPs.

  5. Save the changes.


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